The only change that makes this COMPLETLY overpowered is the totems affecting your raid,
http://www.twentytotems.com/2007/11/...ems-guide.html

Take a look, I think 25 shaman stacking Stoneclaw ( Yes Stoneclaw ) to Mitigate 25 attacks in 25 mans

Totem of Wrath 25 shamans x 3% = 75% bonus to crit and hit. Add in gear with +crit and you doubled your damage.

Healing Stream, OMG say about 2xx or 3xx Health with +healing in WOtlk with healing gear probably, about 5000-7500 every 2 seconds.

Grounding Totem, lolscrewcasterbosses

What do you think 25 shamans could accomplish if they stacked within 30-60 yards to gain 25 totem effects?

EDIT: Also this info on totems affecting raid is confirmed at the Shaman Booth in the WWI.