Seriously though, I've been thinking about it...
Wouldn't work at the moment as games aren't good enough yet.
However, in the future you could use virtual reality to do a lot of your sparring during rest periods, injury free
What I mean is- train normally, but use a virtual reality simulation (controlled via your mind/nerve impulses) during rest (could even train with other people with no risk of injury, concussion etc). Especially useful say if you had been injured and you're out of action for a while (in order to keep your mind sharp).