As has been stated, this won't be an obsticle in prolonged periods of play, because if you are going to excersize, you want to be dressed appropriately, the issue will be in introduction.
A friend comes over and you say "hey try out this game I just... oh nevermind..." This type of marketing is huge for motion gaming. Skirts and suit jackets will not serious hamper it, but if there more conciderations then there is a problem.
One more thing: it sure would be nice for some developers to accomidate people missing one or both arms. Just because the standard control system isn't tailored for them, shouldn't mean a control system that could allow them to "jump in" should ignore them.
"You can never jump away from Conclusions. Getting back is not so easy. That's why we're so terribly crowded here."
Canby - The Phantom Tollbooth
