At Microsoft's X06 Conference in "Barcelona" they confirmed that the "previously unannounced major franchise" that was being released today is DOOM.
The XBLA version includes upgraded resolution, 5.1 support, 4 player split-screen, both local and online 4 player co-op as well as Death match. Unfortunately it doesn't support WS (although it does allow you to stretch the screen).
For those of you who are Achievement whores, here's the list.

Comments
Mike Kelehan
62362
Hexxagonal
23061
Measure76
23717
Resolution is upgraded. Graphics, not at all. If it still had the classic resolution, it would do a poor job filling the screen, like frogger and some of the other classic arcade games.
Multiplayer doesn't work quite like I remember from my highschool days... but still pretty sweet.
Hexxagonal
23061
But mulitplayer expecting
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