Kind of like 3D vision can not exceed 60 fps, but really what is the difference between 60 fps and 100 fps? I mean your not gonna get some advantage based on 60 vs 100. So I don't think they cap the fps for "fairness". I could be wrong I dunno, but just my opinion.
Well, it'd be capped for fairness if they tied a bunch of speed-related stuff to it like they did to FFXI, but that's just bad programming (was bad then... it's worse now).
With the hardware requirements and recommendations being as high as they are though, it'd be really disappointing to see them cripple the game like that