D3 combat: good, I enjoyed all the classes
D3 skill system: quite bad
D3 itemization: ...ehrm..let's be kind and say the worst ever (yes, I've been very kind)
D3 endgame: there is no game (campaign is over in mere hours) so there is only endgame...and a not too interesting one at that.
Freedom of choice given to the player: nonexistent...oh, wait...I can change the color of my gloves...meh
I don't want D4 to be an improved copy of D2 or D3, I'd like for it to be better than both.
No, I won't set my hopes too high.