I have noticed that out of all the upcoming E3 game reveals there are only a select few games being developed for the 360. MS stated that the 360 would be supported until 2016 but I think that is going to be very limited "new games" wise. Sure they will support the xbox live side of things well into 2016 but I think the new games for the console are just about done and dusted.
There are a few games now I want that I will only be able to play on next gen so looks like it is finally time for me to upgrade. I think I will wait until the release of the 1Tb xbox1 console and get that since it seems all the games get loaded onto the hdd these days.
(interestingly enough shadow of mordor installed itself onto my 360 hdd, it did not give me an option not to install it.)