all totems are currently party only. not raid.
The fact that they stack however is a different matter.

most totems will become raid-wide in WOTLK, but will the ones that stack still stack? who knows.

I can't imagine what your raid of 25 shamies will be like if Wrath stacks and is raid wide... 6% spelldmg x25 and 3% crit x 25 >.< that's alot of damage.
I doubt they will stack however.