I ran the first 2 dungeons on Wërth. Still playing Arcane spec but it's different. Started out playing my old style and only pulled 13k DPS in my Cats epics. Better than the 10k DPS DK but shamed by the 21k DPS hunter
Added Frost Bomb to my rotation, and carried what I was doing with my priority system, and topped the charts with 24k DPS on the next dungeon.
I do miss the skill tree, but really, everyone ended up with the same builds anyway, I guess. At least with the new system, you can alter abilities as the need arises.
Pet battles are a neat little mini game too.