I'm assuming Halo 4 will be at the end of the Xbox 360 lifecycle, but when?

Probably a launch title for the next xbox.

It very well could. I think it depends on when they plan on introducing their new console.

Maybe 2-4 years after Reach, unless the prequel is supposed to be 2-3 games.

I can see Halo 4 having a big launch, bigger than 3.

I wonder whether Microsoft would delay the release of Halo 4 until there is a higher installed base for the next Xbox, or have it as a launch title. That is assuming that it would not be a late Xbox 360 release.

No offense but everyone wanted to see how Halo ended, Bungie had said Halo3 would be their last Halo game and wrap up Master Chief. I know many people were hyped up about seeing the end and the game left just a little room for a sequel. I don't even know if Halo4 will have Master Chief return since I think 343 will want to do something unique with the franchise.

Too be honest this could be the end of Master Chief, I am looking forward to seeing a new Protagonist in the series. Maybe a new Spartan. Or league of Spartans. Somebody new would be awsome! As for when we'll see Halo4. Probubly a launch title for the next X-Box and it'll probubly appear in 2011 when the next generation is set to start!

Marathon franchise reboot starring Master Chief please.

Halo for XboxPortable will have him for sure as it will make the console sell more but im not sure about the 4th one.

A *little* room for a sequel? the end of the Chief? Hardly. His final words were "wake me, when you need me." He'll be back.