I will continue to main priest, no doubt. I have only ocassionaly strayed from the true path of priest healing, but always redempted myself and returned. I will probably play Zinn the way I've always done, level her as smite-priest, which for once will not mean holy spec but disc spec, and then keep her as my raiding char. There are some things I wish to change however.
Zinn has been undead since the start. I like undeads, especially the females. But now I feel like it might be time to go another way. For example I've always wanted a female troll priest. I just like the way they look when casting (so imagine my happiness when I got the troll-transform thingy from the Echo Isles event). Also troll racials are better for healing than undead racials. Although I actually use Will of the Forsaken fairly often in raids, I'd use Berserking even more often. So Zinn might turn into a troll.
She might also turn into a goblin however, since I read that goblin racials are pretty neat for healing. 1% haste straight off and those jumping rockets could really become handy. I have no idea how a healing goblin "feels", since I haven't checked any videos or played the beta, and the "feel" is rather important. I don't want my character to feel like a misplaced fridge trying to figure out what to do, like female tauren casters or female troll melee look like. I want every cast to feel like something is really happening, the more the character puts into it the more I like it generally. Another question is if 1% haste at all times will be better than 20% haste when I need it. Will 20% haste just overcap me? Or be the savior of the day? Hard to say, so this is one thing I have to figure out before Cataclysm. That Zinn will seize being an undead is pretty certain however, unless Blizzard revamp undead racials into something awesome.
My druid is probably going to undergo the biggest change when Cataclysm comes. She happens to be a female tauren and if you read what I said about them above you might've figured by now that I really dislike playing them. My shaman used to be female too, but I sex-changed him to male. It's funny because I never played him and as soon as I had changed his sex he became one of my favorite chars. Although all of his skills were exactly the same, the gear the same, everything the same (except the name, which I also changed), it felt like a completely new char. I've written about this before, the feeling of the character really makes a huge impact on playing, at least to me.
It didn't bother me as much that my druid was female tauren, since I rarely had to see her anyway. She was always in some shapeshift or another. But now that they've removed Tree of Life I would have to look at her stupid face (or back actually) everytime I want to heal. I could just not be resto. But no, I want to race change her too. Into a troll! But instead of paying for yet another race change I'll just delete her and start another druid. I love leveling so that won't be a problem at all. She doesn't have any cool achievements or items so deleting her won't be a loss. And I'll probably main her as feral. I'll give it a try at least.
I haven't really settled into all the changes made to hunters yet. Focus? Trap launcher? Rotation? Eventhough I always say that hunters are so easy (and they used to be!) they still had what probably is the biggest arsenal of skills which you had to keep handy at all times, eventhough you ended up using them rarely. All the shots, stings and traps for instance. Now I have to sort out all of my skills and figure out this whole focus business. I've tried it some and it seems fun actually.
Also now that all the specs seem about equally viable for endgame (finally) I'll probably make Beast Mastery my main spec. I never liked Marksman and I played Survival all of Wrath so it's time for something fresh. Also I feel like the pet is what being a hunter is all about really, so making it an important part of my playstyle seems like the right way to go. You know, in the same way some rogues feel like daggers is the right way to play a rogue.
I'm not happy about resto shaman healing. That might change once we get Healing Rains and all the other fun stuff I was looking forward to in 4.0, but turned out not to show up until Cata. My shaman is put on the shelf for now. Healing is exactly the same as it was pre-patch, only not as good. Or it doesn't feel as good anyway. When Cataclysm comes I'll probably continue to play him the way I have in Wrath however, resto and enhancement. Maybe make enhancement the main spec instead, but what I've read about enhancement so far doesn't make me eager to make any choices about it right now. Apparently enhancement has suffered as resto, it's all in all the same only not as good.
I've mained warlock, twice. I used to really like the class! But I didn't like the way the developed in Wrath at all. It felt like warlocks were just like a version of mages. None of their huge arsenal of cool utility skills were ever put to any good use. Banish? Nope, never had to use that. Succubus? Nope, never needed to seduce anything. Warlocks were only needed for their soulstones and healthstones, which are out of combat stuff. I never got to show of my neat warlock skills, and that made the class boring (ok, I don't have any neat warlock skills, but anyway!). The changes made to Soul Shard have made me interested however. Here we have a really nice tool that forces us to make interesting choices for our dpsing. Will I use this shard to instantly summon my pet that just died in a fire? Or save it for that Drain Life I will need later on in this fight?
Warlocks are looking up, and I really feel like giving them a fresh chance. In wrath I initially played as Destro, then I switched to Affli, but didn't enjoy it so I switched to Demo. I like both Demo and Destro, but I'll probably go Destro, at least as a start.
Paladins have become loads of fun. There was a time when I played Protadin rather extensively, but then when I tried out warrior tanking I felt like prot paladins came out short. Suddenly the whole rotation playstyle seemed stiff and like it hindered any improvisation. My protadin couldn't pull off the cool stunts I could with my warrior. I still feel like warrior tanking wins out on protadins, but I am happy about the changes they've made so far. At least now we have some procs and buffs to keep track of to optimize our tanking, and that furthers good planning and execution to pull off some nice tanking tricks.
Also her offspec, holydin, which I rarely played because it really bored me (not as much as retridin though, more about that shortly) has become alot more fun. The implemention of some more heals, removing Beacon of Light as the IWINHEALS-skill and having to keep track of Holy Power are all things I've really enjoyed about my holydin. I might make holy my new main spec on my paladin.
I played retri initially in Wrath, but quickly abandoned it because it was just too boring. It felt like no matter how I pressed my buttons I did fairly well on the meters, and where is the fun in that? It felt more like the char played me than I played it. "Press this button now", "Now press this button", like paint-by-numbers, whatever came off cooldown first I used and that seemed to work well enough. I haven't tried retri at all since the patch. The retris in my guild are sad however. Not only has the damage been nerfed, the spec is just as boring to play as it always has been. I should give it a try before I dismiss it I suppose, so maybe I'll level as retri in Cata.
My warrior will probably change the least. He'll just continue to be prot! I might switch him from tauren male to orc female, because I've always felt like a brick (or was it prick?) when tanking as a tauren male and I want the feeling of flexibility that the meleeing orc female has.
I've always liked fire the most when playing my mage. I've always tried to main it but had to abandon it because it just wasn't good enough. I tried leveling her like it, but it seriously sucked as compared to frost. Then I tried it again once I had dinged 80 but it just wasn't as good as arcane. As soon as I heard rumors about fire doing ok in raids I switched her back again, and that is what I am currently playing. I still love it, but I might try out frost for Cataclysm. Frost is interesting too because it has alot of procs and buffs to keep track off, and that seems to be intact with 4.0. I haven't tried it yet but as it seems to be a viable raid spec I might just do that.
I leveled my death knight as tank, and played her mainly at 80 as a tank. I was never very good at it though, and as with protadins I missed the flexibility of warrior tanking. I liked the class, but I didn't like how the runes forced me to play my death knight in a way I didn't want to. I had to pull and handle each group of mobs the exact same way or everything would just screw up. Any suprise pull was a problem, because most of my runes would probably be on cooldown. The longer a warrior is in a fight, the easier he can handle any unplanned situation since he'll be high on rage. But the longer a death knight is in a fight, the less chance he'll be able to handle an unplanned situation because all the runes will be on cooldown. I don't enjoy playing a class that is at top when out of combat! I don't want a class that is at their max potential from start, and then dwindles down as the fight continues. I know that's not exactly how death knights (and to some extent paladins with all their cooldown based skills) work, but they sure feel like it when you compare them to classes like warriors.
My last char to level and as such I haven't had much, barely any, chance to test it at endgame. I have been keeping an eye on rogue changes in 4.0 and what rogues think about them. As I've mentioned before it seems like my favorite spec Subtlety just doesn't cut it at endgame and I am therefore thinking about going Mutilate instead (I never liked Combat, which just feels like a weird version of fury warrior). My rogue is still sporting the BoA gear and weapons and I am divided between making a serious rush before Cata and gather some real gear or just leave it since I'll switch anything I can get once I start leveling again anyway. I'm leaning towards the second option though.
Right now I'm not entirely sure in which order I'll level my chars. Usually that depends on what I feel like playing the moment. Since I'm still maining my priest, I'll level her first no doubt. Paladin and warrior are surely coming next, since I enjoy tanking with those classes. And then, anything can happen!