In 2010, Microsoft announced it would be publishing a game with the working title Codename Kingdoms, an action game that was being developed by Crytek, best known for the original Far Cry and the Crysis series of first person shooter. At E3 2011, Microsoft announced the game's official name, Ryse, and that it would be based around the Kinect motion sensing device.
Other than a few seconds of pre-rendered trailer footage and the fact that you apparently control an ancient Roman warrior in the game, very little is known about Ryse at this point. Now there are rumors that the game won't be released for the Xbox 360 after all. Instead there are signs that the game is being made for the next generation of Xbox hardware.
VG247.com reports that Ryse's senior level designer left Crytek to work at Microsoft. However, the LinkedIn profile for the level designer lists Ryse as a "X-Box Next Gen" title, rather than an Xbox 360 game. There's also a more flimsy report at NeoGAF claiming that a person who attended a lecture on CryEngine 3 overheard a Crytek rep saying that there was a "big chance" that Ryse would now be a next-gen Xbox game.
Naturally, Microsoft has already said that the company will not comment on any rumors or speculation, as they usually don't when asked about these kinds of questions. The fact that Microsoft has been nearly silent about Ryse for well over a year now would seem to suggest the game is still a long way away from being completed.