I’ve been catching up on my blog reading so forgive me if this is old news but I think it is very cool indeed, and that is the DSL Tool kit version 1 is available and is part of the new Visual Studio 2005 SDK Version 3 which can be downloaded from here.
If your are not quite up to speed with what DSL, or Domain Specific Languages are there is no better place to start than here which is a URL you will want to add to favourites.