I love that the ui is not so static anymore and I am sure that especially a lot of new users will find this more comfortable, to change there ui ingame instead of using addons to get the things where they want them to be.
There are a lot of addons i would like to get rid of, because you permanetly have to update them, you get lua errors etc… So I like every step that goes in the direction to implement things in the game instead of having addons for it.
I like the new talent trees very much… even if there will be theorycrafters that will tell you the absolut best way to do, there will still be people that don’t need the best talents in their guild to compete or with the content they do. So it leaves you with more personal choices, instead of picking 5 different talents (which are the same in almost every situation for some classes) and thats it.