Flame on 20 May 2012
Having Halo 2 Anniversary would be a pretty good launch title to get the momentum going. I also agree with everyone else. 2014 seems way out there and launching it in any other season besides fall wouldn't be the brightest move. Two and a half years is a hefty waiting time so yes, 2013 is the more likely launch year.
Although the next Xbox will probably launch in 2013, I wouldn't be surprised if Sony actually waited until fall 2014 to release their next console.
