I'm disapointed that I have to make the same post every year ...
GDC is not a conference like E3, and there is not (typically) a great focus on announcing games beyond showing of new technology. The reason why Epic, Valve, id, Havok and Microsoft have such large booths (in comparison to a company like Nintendo) is they are trying to convince developers to use their game engined or development tools.
A "Big" announcement from Microsoft, Sony or Nintendo at GDC would more likely be that they have produced a royalty free 2D engine for producing downloadable games for there console than a big exclusive game ...







