We always have some cool ideas on deck, and kind of the inception of Infinity Blade began as a discussion around: "If we were going to make a Kinect title, what would we make? What would a Chair Kinect game look like?"
That discussion happened, you know, a year and a half ago. We had this really cool design, and it's not that dissimilar from the game you're playing today; it's just been refined and adapted to the iOS screen, which honestly I think is where the design works the best.
Having played Infinity Blade and used Kinect, I'm glad the studio opted for an iOS release. While I'm sure the game's scale would have been larger if it was an Xbox 360 Kinect title, Infinity Blade works perfectly on the iPhone and iPad with taps and swipes. Also, it shows off Unreal Engine 3 on my shiny iDevice.
Chair is owned by Epic Games and there were rumors that the VGA reveal from Epic would be Gears of War Kinect title, but the announcement--whatever it was--was canceled at the last minute by Microsoft.