I know it seems far-fetched, considering they have said it will be 360 only, but it makes sense in a way. If they do release it at the end of 2012 then they probably wouldn’t put out a console for another couple of years. I mean, if it was to come out a year later, they may as well hang on to Halo 4, it would cripple the next console if their biggest franchise was on a previous console, even with backwards compatibility people would want games that make the most of the new hardware, so halo 4 would not drum up the same amount oh hardware sales it normally would. This generation has gone on long enough, and with the Wii-U launching at the end of the year, their is no no doubt that Microsoft and Sony are finishing up their new consoles, considering the current gen is now really outdated hardware wise.
It would also explain the lack of information. I have no doubt if they did release it on the next gen console it would also be released for the 360 too, to try to imitate Sony’s strategy for keeping the PS2 alive for a while after the PS3. But 343 would not like to show clips or screenshot’s of the inferior version, they would want to save things like that until they could show off the game in it’s best state (remember battlefield advertised with very little 360 footage, mostly PC with a little PS3) They want to save all this information for the big reveal, imagine how big it would be for Microsoft, revealing a new halo game on a new console, it would launch the hype into overdrive. Halo 4 as a lunch title would guarantee a strong launch for this new system. If they were to announce this, they would probably want to do it in the first quarter, than build up hype through the summer and the fall.
So what do you think, a release on both consoles, to maximize sales revenue, guaranteeing a successful launch for the new console, and guaranteeing a life for the 360, it would be a hugely profitable move from Microsoft. And remember how 343 flat out denied Halo CEA. I may be completely wrong, but i live in hope.