So we did the first three bosses in ICC this evening (we actually made a fast attempt on Saurfang too but wiped at 30%ish) and here are my impressions. Here be spoilers by the way.
We did this on normal and this guy wasn't too hard. He does a spike which stuns a random raidmember and does dot damage until the spike is destroyed. He also does some sort of ice that moves along the floor and that needs to be avoided as well as a Bone Storm which means he whirldwinds around the room. Should also be avoided. None of these were any real problem though but we had some issues with his Cleave. It does approximately 50k dmg divided to two targets in front of him (preferrably the tanks). Before we had gotten the moves in with moving from storms and ice and spikes we had some trouble with the tanks taking 25k dmg spikes. Also I was healing the first boss on my less well geared shammy because we had 4 (!) priests in the group. An overall not so interesting and not so difficult fight, quite straight forward.
First time I heard her name I thought she might've had too much garlic in that sandwhich. She has two phases, one where you nuke down her mana (shield) and one where you nuke down her health and effectively ending her. The room she stands in resembles the one Blackheart the Inciter resides in in Shadow Labs, but the mobs aren't as annoying. I remember you basically had to use cc back in those days but that wasn't needed here. She doesn't do anything too hard. She random targets and shoots shadow bolts which are easily healed and puts out a green Death & Decay which is easily avoided. She is untankable in phase one and the tanks should instrad focus on grabbing different adds that spawn. The adds didn't pose much of a problem either except for the Deformed Fanatics that spawn from the dead Cult Fanatics. They hit like "a m-f'n truck" like someone put it on wowhead.com and I agree. Should be kited. Second phase was really easy and we got through it before I realised we'd started it basically.
After Deathwhisper you'll get teleported to a ledge where the good guys fight the bad guys. A guy in our raid accidentally got into combat with them which teleported anyone close by right into the middle of the fight and most of us got one shotted. This happened a couple of times before we realised what was going on and could collect ourselves. Apparently the fight had bugged out so that we would get instantly teleported as soon as we got close to the fight. Or maybe it is supposed to work that way. I'll notice next reset... We managed when we were ready for it though and worked our way to the Gunship.
I found a good tactic over on Wowhead which worked for us and I'll therefor share it with an important addition. When you start the fight you'll fly alongside with the enemy ship. Have two people working the cannons and everbody else staing on your ship. As soon as the mages appear to freeze your cannons you have one tank jump over to pick up Muradin and the dps jumping over to kill the mage. As soon as the mage is dead, everyone jumps back. If the tank and the healers stand on the ledge the healers can effectively heal both tanks. Important Addition: Muradin stacks a buff on himself that increases his damage done by 10% per swing or so. After 20 stacks his every melee swing will do 30k dmg on a tankgeared char. That is about 30k dmg every 3 sec. The tank must therefor jump back with the others when the mage is dead to reset his stack count. Rinse and repeat. Doing this the fight was very easy, but before we dicovered his dmg buff we had some trouble...
After the Gunship fight is over we didn't really know where to go. Maybe something had bugged out for us but we couldn't speak to anyone or see any portal leading anywhere. We jumped down, giving everyone levitates and landing on the previous ledge that had gotten us to the Gunship. The fights where still going on down there however which means some landed in them and died. They then discovered you needed to be somewhere completely else to find Saurfang. We told everyone to die and teleport to the right place. We still don't know if there is a better way to get to him, but of course there has to be. The same guy who had bugged the event from the start said he had gotten an npc-whisper to jump. No one else got this whisper though... Hmmm.