So the complaints I've heard so far have been fairly loud on a few points.
-Distracting Shot gone. This hurts being able to solo old content and other useful times in a boss encounter. A tweet came from a dev saying to compensate, they will increase the range that Growl can be used. Although that still doesn't address that when you taunt, you want the mob to attack you and not your pet?
-No CDs if you talent passives. Yeah, its looking weird but it seems all classes are heading this way to some degree.
-Serpent Sting removal. Yep, people are madbro here for dumbing down rotations. Although some point out that most of the time, you shot it and then forgot about it as long as you renewed it on time with your focus gainers.
-Overall feedback that they cut too much. This is what I'm hearing most...Blizz cut too much.