Hmm. True. Bungie would be v busy with Halo2, but they could concentrate on working on that, while Valve (who did the PC version - which is online) could maybe work on "upgrading" the XBox Halo1.
An online Halo1 would be a massive seller & would probably kill-off XBC. They could release an online & multiplayer only budget version, & I'm sure loads of people would buy it if they did. And it wouldn't impact negatively on Halo2 sales, as that's not out for 6 months or so.
Still sounds too good to be true though