I don't think they're bothering with a Merit system yet because 50 isn't going to be the final cap. I suggested the same idea a while back, but then I realized that right now, yes we have all of these high levels (at least you do, I'm still 29), but once the level cap is raised you'll be able to keep leveling each of those up more. I'm betting they will add some sort of system like Merits, but we won't see them for a while until the cap has been raised. Perhaps 70+ or something.