I'd hope I'm never the cause of a change that effects every Shaman that plays this game O.o, but they have been wanting to nerf Lightning Bolt / Chain Lightning spell damage co-efficients for a long long time. Our burst is pretty high still and this change is very beneficial because it makes Resto Shaman less effective as DPSing compared to the spell that should be doing damage. Resto can pump out 750 dps when not needing to heal.

The expansion is going to have scaling on damage for everyone but HP is not going up a lot, maybe 2-3k from what I have heard. Blizzard's focus is on mitigating damage now and finding ways to avoid it.