I dont know if it was stated but i learned yesterday that if you have elemental dualspec with the totem of wrath glyph, you can keep the extra roughly 100 spell power when u change back to enhance. I guess its because though totem of wrath is a talent based skill, the glyph "could" be used by an enhance shaman (even though it would do them no good). Only lasts 5 minutes, but most hard modes in ulduar dont last long anyway. Something nice to do before every boss pull if u want to squeez out some more deeps.