They already use it in games, Natural Motion licenses animation middleware to game devs. I've used Endorphin extensively and I know they've used it in a few games, Fight Night 3 comes to mind right now when it comes to sports. There's some pretty awesome things you can do with mocap samples in it to make them completely nonlinear.

with calculations the possibilities are limitless. I for one am getting tired of the same canned instances governing potentially different situations. Take NBA 2K for example. That game is riddled with canned instances and animations. It sucks because sometimes you'll get pushed away when you've got a good angle on a drive, or you'll be forced around when you were nearly past someone. Don't even get me started on foul calls, because those are very obviously random.

Every sports title at the very least should be implementing something like this IN CONJUNCTION with motion capture. It can only help things in the end.