Xbox Live has had a rocky history with projects being announced and then never quite getting off the ground. From the recent announcement of the cancellation of 1 Vs 100 to the proposed cross-platform gameplay offered in ShadowRun things never seem to materialize. It is not a lack of initiative or technical wizardry that killed cross-platform gameplay but the very platforms themselves.
Microsoft experimented with cross-platform online play well after ShadowRun according to Voodoo PC founder Rahul Sood. Prospective titles would have included the Gears of War series among others. The reason development stopped was the improved accuracy that the combination of a keyboard and mouse provided. Even the most skilled console veterans could not keep up with PC players.
It is sad that Microsoft could not get cross-platform gameplay working. Wouldn't it have been neat to try out Halo 3 mutliplayer on the PC? The Xbox 360 is an excellent console but perhaps Microsoft is ignoring the PC market as a whole by not releasing major releases on Windows.
Hulu Plus Confirmed for Xbox LiveRidley Scott Plans User-Generated YouTube Documentary