This one looks really interesting: A VS 2005 DSL for GOF Patterns . Shows how much people are really getting into with the DSL toolkit and producing really useful applications.
Who knows maybe someone will pick up Gregor Hohpe's EIP stuff and make a DSL out of it. Theres already an invaluable Visio stencil of the same available on his site which i've used extensively.
Im keen on exploring this area further. Should start collecting links on real life examples of DSL's and centralise that somewhere. In the architecture work im doing for a really large scale integration project, im considering going down the DSL and GAT route soon, especially in the Biztalk area. There so many reusable patterns that keep surfacing over and over again.