It has been announced at E3 that Minecraft will be ported over to Xbox around Winter after the Official Release of Minecraft.
To get the most up to date Minecraft on Xbox info go here:
http://www.youtube.com/watch?v=aZ6eAF8Magw&list=UUvzCasuaQi80mAHkPpHsnew&index=1&feature=plcp
