Well, you've had almost a week to play around with the new version of your favorite class. Now that it's had a bit of time to settle in, have you come to terms with your less crowded action bars?
As a hunter, the ability I miss most is probably Scatter Shot. It was one of the most iconic hunter abilities and it just feels weird not to have it anymore. I've had several instances lately where I wanted to press it only to be reminded again that it's gone. Second place would be Kill Shot for the survival specialization. I realize all specs had to be trimmed down somewhat, but I personally think they took it one step too far with with survival hunters.
The ability I miss least is probably Serpent Sting. In most cases I would cast it at the beginning of a fight and never bother with it again, which I think made it a prime candidate for pruning. The ability still exists in passive form for survival hunters, but I'm glad it's gone in its old form. Second to that would be Aspect of the Hawk. Remembering to have an arbitrary button toggled on for 20% more damage wasn't exactly compelling gameplay.
What about your class? What do you miss? What don't you miss?