Ulduar raid composition?

[Radoznali]

i know that because of dula spec its slightly of point,but i was wondering how many tanks are needed on bosses? 1 up to how many?Are all 4 tanks equally capable to tank contnet in ulduar that is know of yet or are there fights like Sarth 3d were you need Dk or druid on boss?

[Debased]

Ahh from the PTR it seems like usual, some tanks excel (a lot) in certain places. 3 tanks is good enough for 25 man so far.