I think it will probably come out in 2012-2013(likely 2013). I think there will be 2 sku's one with kinect 2.0 one without priced at 299 and 399 or 349 and 449. The 720 will initially be sold at a loss(id guess between 100-200 dollars worth) and will be noticeably more powerful than the 360. Id say by the end of the gen some games could look as good as the samaritan demo we saw.
I dont think they will abandon their core audience. I think there will be some kinect focus but also non kinect stuff halo 4(really hope it gets delayed for 720), 5, 6, gears, time splitter, mass effect mmo or something.
Halo MCC will sell 5+ million copies(including digital)
halo 5 will sell 10 million copies(including digital)
x1 will pass ps4 in USA, and UK.







