You can net a 360 cheap now. You still have major games coming out this and next year, Halo, Gears and Assassin's Creed. I think it's pretty much in stone that the next Xbox will be fall 2013. That is a long time from now.
but 2013 or 2014 release dates are all just speculation on the fans part at the moment correct?
Mircosoft themselves have made it clear that they do not intend to release the 720 until the 10 year life cycle for the Xbox 360 is over which is not until 2015.
Kinect was considered by MS as a life extender for the Xbox 360 and it's clear they have no problems on waiting for a new system. No doubt there heavily testing it to ensure no more RRoD.
At best they may announced something at next E3 but no new systems for 2 years I say.
Definitely Xbox 360 ! It works great, it looks great, cheap and with a kinect it is awesome. You shouldn`t wait any longer and enjoy it with that sexy new home cinema