That is a great idea. It would be hallu-fun and nobody could whin anymore that 2 isn't like 1 and 3 isn't like 2 and 3 isn't like 1 and 1 isn't like 2....
FYI...I played Halo 1 online for two years...you just need a PC or a Mac. The game costs 30 bucks or so these days and there is still a group of 5000 or so that play regularly. It is awesome

....although I'm prolly playing Halo 3 99% of my time these days.
To have all three multiplayer releases on one disc though....Wow, great plan!
BTW...there are a couple maps, some vehicles and weapons that are on the PC release of Halo that are not on the Xbox version. Also....there are hundreds of custom maps available for download.