I thought Healing Stream totems stacked. Not sure why I think this though, I shall go try to find out. I know mana spring does not stack.
Edit:
"WoWwiki" wrote:
Unlike Mana Spring Totem, the Healing Stream effect stacks with that of other shamans. If you somehow end up in a group with three or more shamans, the cumulative healing can be very significant.
From here: http://www.wowwiki.com/Healing_Stream_Totem
And, while I didn't see anything "official" anywhere, in the few threads I read pretty much everyone agreed that ToW can stack. Which I never knew and is insane.
Edited, Feb 14th 2008 11:20am by Khalane Edited, Feb 14th 2008 11:25am by Khalane