Watch this short screencast to learn the tools needed for XNA game development for the new Windows Phone 7 platform. If you are a .NET developer using C# programming, you can get up to speed quickly with Microsoft's XNA Game Studio 4.0, part of the Microsoft Visual Studio 2010 Express for Windows Phone 7 toolset.
In this screencast, we'll also learn how XNA games are organized at the highest level, and see how you can test your games within the phone emulator. The XNA emulator, however, requires quite recent hardware to run correctly. This especially applies to the graphics card you have.