On the leaked PvP set information, you may have noticed a few oddities. Firstly, +crit (rephrased as "critical rating") was being thrown around like candy (+32 spell crit on a single piece of armor?) and, secondly, a new stat, "resilience" was mentioned. Well, I still consider all of this to be rumor, but the Curse Gaming forums have some interesting discussion on what alpha test players are seeing with these stats.
Poster Daviesh suggests that percent-based +hit and +crit have been removed entirely, and replaced with critical rating, which gives you an amount of both based on your level. And Poster Anders chimes in with precise numbers -- +10 critical rating for 1% to hit at level 60 and +14 critical rating for 1% to crit at 60. At level 70, the numbers shift -- 15.769 critical rating per 1% to hit and 22.076 critical rating for 1% to crit. As to resilience, it's still somewhat mysterious, but poster Ruinx suggests that it's an anti-crit trait (if this is true, that would make it similar to +defense on current itemization).
Of course, the question on everyone's minds is how this sort of change will impact the game. And that's difficult to do without seeing how exactly these new stats will be itemized throughout the game. If we assume it will be itemized similarly to the current +crit and +to hit bonuses, we would have to assume that less (equivalently) +crit will be seen, since it will always be bundled with +to hit. And if the amount of benefit gained by crit rating does change with level, it may end up more difficult for a max-level player to stack +crit for a sky-high crit rate. But as to the actual impact this change may have on the game (and whether it will actually be implemented to the extent described) we may not know until the beta begins and more information is widely available.