Our big green style, cannot be defeated!
-Sgt. A.J. Johnson - Halo 2 - Metropolis
For them to bring Halo 2 multi-player back online would be a bad idea. Sure it was fun, but the community would be dispersed throughout the Halo 3, Halo Reach, Halo Wars, and then the Halo 2 match making, just like Call of Duty. The only reason why this "kind of works" for CoD, is because they have a larger community.
If they did make a Halo 2 remake, it better have Halo 3 graphics, but with a refined version of the engine they used for Halo 3. The Reach engine looked completely fake, & the Halo 3 campaign was supposed to be a part of the Halo 2 disc, but it just would not fit. So, it would be best if they made a Halo 2 remake after all the next Halo installments, which should just end with Halo 4.
I for one want another Halo: ODST game for one of 343s next Halo games, but with more bad ass cinematics. It could be about the ODSTs on Reach which include Buck, Dare, Dutch, Mickey, & Romeo. It would be sick to see what they were doing on Reach while Noble Team was around. I'd rather see them in action over Noble Team.
[Edited on 01.25.2012 3:10 AM PST]