I know people have talked about using a multi-touch interface w/FCP, but the iPad is less than 24hrs old and won't be shipping for months so until it hits the streets and people get units to test and develop on everything is going to be speculation.
I wouldn't be surprised though to see someone try to make a multi-touch control surface for FCP but it would most likely need to have the iPad connected via USB. IP based controls w/the ProApps can be very finicky in my experience.
A Wacom tablet has pretty much replaced my mouse for all of my computing (not just editing) so I'd be down to seeing what a multi-touch interface could do.
Lethal