The Microsoft Visual Studio 2010 DSL SDK Beta1 has just shipped and is available for download!

If you're interested in Domain Specific Languages and want to use tools to build your own DSLs, download it and try it out.  You will need the Visual Studio 2010 Beta 1 bits and the Visual Studio 2010 SDK Beta1 installed first.

The DSL team also launched their code gallery site which contains more information and samples to get you started with DSLs.