Our setup for 10-man looked like this:
Healer: paladin, shaman, disc priest. Paladin on MT, shaman on MT+raid, priest on OT(+raid).
DPS: DK, 2 rogues, warlock, ele shaman
The paladin MT helps the healers in phase 1 a lot by dispelling the magic dot himself, so they can focus on other things and using JoL to smoothen out the aoe from Steelbreaker. The disc priest tosses a PoM in the melee dps from time to time, otherwise he can focus on the OT, who can take considerable damage spikes. Alternatively priest and paladin could have swapped assignements.
In phase 1 we waited for a convenient Rune of Power, then blew heroism with the dps standing in it.
Timings: Steelbreaker dead after 2min20s, Runemaster after 5min, Stormcaller after 9min.
For those interested, our paladin MT frapsed the kill:
[ame=http://www.youtube.com/watch?v=xvMJFdPeJxc]YouTube - Ulduar Der eiserne Rat 10er[/ame]
(sry for german interface, but I think that doesn't really matter. Also you should turn off the annotations)