Too early to tell.

If we get stuck at RoS like Barbs stuck at Inferno in the early stage of the game, the gaming experience will be suck-balls.

Indeed, the synergy of skills makes D3 outstanding.
The synergy of skills made those D2 wannabes, like Torchlight and Path of Exile, pale and old school.

Not only barb, all class of heroes have their own builds and synergy of various skills. It's fun to kill mobs with combination of keys/skills.
D3 development team is genius. Of course, thanks to Jay Wilson too. 



Let's hope RoS will have the same kind of synergy (after all kind of nerfs).