Our regular 10-man made it through the Icecrown Citadel gear check tonight! I'll write up our exact strat when I have more time, but we did end up using three healers.
Druid tank, warrior tank, holy paladin, holy priest, deathknight, rogue, and elemental shaman all stayed in at melee range. Two hunters and a tree (me!) stayed out at range, with the hunters collapsing on me each time a spore came up. Collapsing to a known location rather than spending time figuring out who had the spore definitely made things easier.
We got Festergut down with 12 seconds left on the enrage...but we did get him down!