I don't know how wide spread this is, having only hit 120 Saturday, and not having done a ton of dungeons... but it seems like a serious issue for us.
I ran the Storms dungeon, and we got to the first or second boss, which was a two boss fight. one of the bosses was a priest and was constantly dispelling the dots i placed on the bosses.
As far as I'm aware, this is the first instance of a boss clearing Dots outside of phase changes (like when they go underground). I can't help but think this mechanic might be put into raids, making affliction very useless for those fights.
Likewise, I've seen a lot of another mechanic... the 'smoke bomb' which makes you miss, and certain mobs really overuse it. There is a named wanted poster quest mob in snakeland (He rides one of the beetles and halways through the fight the beetle comes to fight you as well) that was literally dropping a smoke bomb every time the duration on the original ended. It was a royal pain in the ass for a solo target.