Jean-Marc has just announced about our release of DSL SDK for VS2010 Beta1 !
In that posts he covers about the new features we've added, sample and more!
We have a new code gallary page that is worth checking out: http://code.msdn.microsoft.com/DslTools (I planning to write a sample regarind our new WPF databinding features in the next week or two). You can download the SDK here.
Cheers