Microsoft recently announced that it is renaming its textual modelling language from "D" to "M". Check out http://blogs.zdnet.com/microsoft/?p=1631
This would be released along with visual modelling tool called Quadrant.
I have always felt the need for textual modelling language given the limitations of visual modelling languages such as DSL tool kit. I feel these are long due in MS platform given that eclipse platform has taken lead check out http://www.eclipse.org/modeling/