I can safely said that I'm mildly a fan of the Halo Series. I've played the Single Player for all 3 Halo games thus far and played a bit of Halo 2 online, and barely any Halo 3 online (other than co-op). It looks to me like Halo Wars will be a rousing success and we know that Halo ODST will be a success as well in the fall. The question is, where do Bungie and or Microsoft take the Halo Universe after the release of ODST. Here's a few of my ideas (which I know in the grand scheme of things is "diddly" and "squat"
I'd love to see a flight sim based off the Halo Universe. We know that both the Covenant and the UNSC had fighter pilots so why not give us a flight sim type game? I think it would sell extremely well and be quite popular on Live.
LEGO Halo- I know this one has been discussed already and although I'm not a fan of the LEGO series of games, I really think that a Lego series based off Halo would sell millions of copies and introduce a whole new age group to the Halo Universe.
How bout a prequel to the first Halo that's not Halo Wars? The idea of playing with multiple Spartans against legions of Hunters and Elites would be intriguing, and the way I see it, gamers have already "Finished the Fight", why not let them "Begin the Fight" as well.
I'd like to see a squad based Halo Shooter (the way we all thought ODST was going to be). Hell make a young Sergeant Johnson the lead character and have a squad under his command.