Did a full clear of Ramparts last night with four toons and no heals. Lost the tank on one pull, not sure why. Lost the lock on Nazran towards the end of that encounter - I think he was critted by a fireball. Once my shaman gets high enough to do these instances I should be able to progress much further. Killed Omor and took no noticeable damage on any character even though I botched the pull (rogue caught initial aggro and pulled him too far from the group!).

Right now my dps distribution goes like

Rogue - 35%
Hunter - 32%
Warlock - 22%
Warrior - 11%

Clearly I have an advantage in that all my guys are at least level 68 and ramps is a level 60 instance. I'm finding controllability so far to be reasonable.