For all of the advances in motion capture gaming, you'd think Lucasarts would have already banked on a decent "lightsaber simulator" for either Wii or Xbox Kinect. Massive there for not being on the ball. Could be literally printing their own money.
The current version of Kinect is not advanced enough to track the level of motion needed for your proposed simulator. The version coming out for the next Xbox should be improved, but no one knows yet to what degree.
Yeah... They have tried, several times, but it's always not worked like you think it would. Part of that is, I'm sure, accuracy of the tracker.
MS really oversold the tracking on the Kinect when it launched. It's not nearly as precise as people thought it would be based on the marketing. Reminds me a lot of the Wii when it first launched. Turned out the wand was mostly good for "waggle and wave" style controls. Real 1:1 mapping didn't hit the Wii remote till the upgrade a while later.