The thing is, when people think of swordplay, they think of making 1-on-1 movements where the sword reacts exactly like you move it (the controller or your hands) in real life. But so far, every motion controlled game implements a set of gestures that are linked to in-game actions. It has never been about mapping movements 1-on-1 to the screen. There's always an abstraction layer in-between.
Pretty sure this has been gone over by some game developers, but I'm not in the "google for references" mood today.
Basically, 1-to-1 sounds great on paper -- until you realize that in order to feel like a expert swordsman
in the game, you have to be able to control your body and muscles at the level of an expert swordsman in real life. People generally don't like seeing a 1-to-1 mapping of how clumsy they are projected onto the screen.
The Wiimote Plus is pretty capable of doing 1-to-1 mapping, it's just not something that's really fun.
A similar style of game, the guy who made X-Plane once released a proof of concept game called
Space Combat (taken down now) that was
realistic space combat. It was only fun to simulation geeks, not something you could actually build an appealing game off of, because real life isn't terribly fun.
