I put it like this.
Shut down Halo 2 when you have Halo 3, ODST, Reach, and Halo 4 on the PC. Till then.
Leave it be.
I hope this doesn't prevent me from being able to play the campaign...
Impressed the Xbox 360 can even handle the new titles coming out. Was worried when they did the 'behind the scenes' with ODST and said they had to "fake the rain" because the hardware couldn't handle Rain (rain drops).
-next gen Xbox can't come out fast enough, don't want to buy a 7yr piece of hardware only to replace it in ~2yrs