Well, there aren't a lot of stats left to choose from. They want gear to be meaningful to more classes and specs at the same time. So out of the 3 stats that there are left (Mastery, Haste, Crit), I think they will make all of them useful for us. Haste will probably work something like you said, mastery stays roughly the same and crit will probably be a bit more useful.
That being said. I want to be a tank and stacks defensive stats. I don't want to get gear with crit and haste. Bears have been doing that and after 7 years of playing this game I still have absolutely no idea how they work