This has no bearing on anything at all really, but your talk of "off-hand" made me think of this: There should be a lefty option for FPS games. It'd be purely cosmetic, just showing the character's gun and hand on the opposite side of the screen while the aiming and gameplay remains the same. Well, in a game like Halo the assassination animations would need to be different as well, but yeah. I'm surprised that I hadn't heard anything like this before, considering the way lefties griped when Nintendo added waggle and turned Link into a righty.
I'm right handed with ambidextrous leanings so it really doesn't bother me on any level, it'd just be a neat idea and add to the immersion for those types.