Will the Xbox 720 be able to do 4K HD?

[ironmanDX]

Giving that the 360 can natively only do 720p this gen and the ps3 even less than that (640p, look t up before you throw flame at me) I'd expect 1080p native and maybe some sort of update later on to upscale to 4k, 3d isn't even mainstream yet.... Why would they push 4k?