EBWorld will no longer be accepting pre-orders for the PC version of Halo, as they were informed by the "higher-ups" that Halo would be an Xbox exclusive title and to cease accepting pre-orders for the game. Considering EBWorld will take pre-orders for literally anything, this could be some pretty strong news that Microsoft plans to keep Halo off the PC... But - I just asked the official PR rep who handles Halo and he says as far as he knows the PC and Mac versions are still on, and will know more next week.