Well, there's two things.
For one, even when PD0 was still listed under GC, it still had 2005 as a date. Which would have been the launching of GC2.
Second, that's prior to the new look, the anime style. Why did MS or Rare decide to go with that look? Maybe because of the developement time--though it's not cel-shading like everyone is thinking (unless it's a new method since it has multiple colors + fading).
But yeah, with slew of FPS on the xbox, you really don't need too many more--platformers will brand name is what's needed because games like Voodoo Vince isn't going to sell.