I don't get why a controller patch wouldn't be readily doable. I can understand that mapping gestures to a button-and-stick scheme is misuse of Natal, but I bet there will be more than a few games that get that sort of patch (unless MS can restricts that on grounds of quality).

I would imagine Microsoft sees all of the 'motion controlled' games for Wii, and doesn't want them. Motion controls don't make a game better if they aren't thought out, so my guess is that this is Microsoft's attempt at QC.

Not surprised, there's no money in it for Microsoft.

Revenue is based off of new game sales, not hardware sales, and not used game sales. Patching older games would increase the catalog of 'natal-enabled' games, but Microsoft wouldn't get much ROI on it, if any. Only Gamestop would benefit in its used game sales. By forcing publishers to re-release, they gain new-game revenue a second time around.