thing i don't like the most so far.... every other class has killer stuff now that completely owns my 5 shamans in AV.. here are just a couple of examples

druids and that new hurricane thing they do,
paladins and just about everything new they do
hunters have some new thing too, i hav eno idea what it is...
and lastly... (but most importantly)

WARRIOR'S BLADESTORM I HATE IT - it just kills my shamans in 2-4 ticks