Is seriously think we already reached a point where a single game can no longer sell a console. People who bought a console for a single game have already bought one. Now its all about those people who are still sitting on the fence looking for overall value and the size and quality of a gaming library.
However one way Microsoft can entice the consumer to pick up their console is to package this year's Halo ODST as a bundle for next years holiday after Halo Reach releases.