We've all had a feeling that Microsoft is holding back some pretty big surprises (or at least completely reasonable revelations) when it comes to Windows Phone 7 Series and gaming, and here at GDC this week it sounds like we're going to get a little glimpse into that. Microsoft is unveiling its new XNA Game Studio 4.0, which lets developers work on games for Windows Phone 7 Series, Xbox 360 and Windows PC. The integration with Visual Studio 2010 that we saw the other day allows developers to build a single project and then make slight modifications to let it run on each platform respectively. Most importantly, Microsoft
