Just a pool of communes and skills that imms can reward shamans with above and beyond the basic shaman kit. Some of these might even replace current communes - improving them in some vital respect.

In this way, we can also push shamans into the faux-druid area. I've always wanted a real cave priest. Or sea priest. Druids are pretty much 'above ground, open air, only' with no real indoor or underwater communes. If druids were so well identified as a seperate type of priest, I'd suggest just mashing the two together. As it stands some overlap really isn't a shame if it means we get some interesting types of shaman out of it.

Druids will still be king of charmies though Shamans are very much the solo type.