Or "I Need More Keys for Binding!"
So this is an issue for some people and/or some classes, I'm curious why Blizzard doesn't look at trying to take a Guild Wars (one, because I've not played two) approach where you have a limited number (now that I think about it, they kinda did this with Diablo III) of ability slots, and you have a wonderful plethora of abilities, but you can only choose a certain amount of them. Now, let me clarify, that I don't think the number of active abilities should be 6 like Diablo III, or 8 like Guild Wars 1, in fact, that was my chief complaint about Guild Wars 1, was that I get all these awesome abilities, and have to pick only 8 (was particularly frustrating as a ranger or whatever, because I had to use one of my ability slots just to have a pet).
If ability bloat is truly that big of a concern, and if they want there to be meaningful choice back in the game, this seems like a better way to do it than fucking around with the Talent Tree or just killing off abilities people liked.
EDIT: The new Talent Tree does kind of do this a little (it also gives you a couple neat choices where it's an active ability versus a passive ability, or even an modification to an existing ability), but it's obviously not 'enough' to fix the issue of "too many buttons".