I think most people are going along the same artifact paths (i.e. they are choosing traits in a particular order according to a guide), so not too much diversity there IMO apart from relic choices. For example, if you're fire, then pyretic incantation is a must-have and you'll want to get it as soon as possible. Other classes have similar "must-haves" that are just insane dps boosts.
However, in regular talents (for PvE), I feel like there is a lot more diversity than in WoD. A lot of the rows have at least two "good" ones, and you can choose one depending on your style/AoE vs. single target. There are still occasional rows with "must-haves", but they've done a better job of presenting some cool choices.
In PvP, there is definitely a lot of build diversity (since you have artifacts + talents + honor talents). You'll probably find yourself switching talents around a lot, at least for arena.
