I honestly wouldn't mind talent trees (per class). It would be nice to be able to influence your stats with something other than gear. Sure, you have bonus stats, but that covers everything. So if you dump into mnd and decide you want to use something else, your other classes won't be what they could be.

And it really is a bit boring as far as customization goes. Aside from whoever has better gear, there's not a good way to play around with your stats. It's about the same across the board.

edit: then again, you have games like gw2 that never quite could get it right, with the devs always messing things up, incorrect tooltips and skills not working properly...