Gerardo de Geest, Antoine Savelkoul and Aali Alikoski of Avanade have an interesting presentation and article about building a framework to support the evolution of languages using DSL Tools. Based on this work, Avanade hopes to be able to migrate models from the Avanade SOA Factory to Microsoft patterns and practices' Service Factory Modelign Edition.
P.S. Just came across a paper on MSDN called "Building a DSL for an Existing Framework" also by Antoine and Dennis Mulder. Not sure how I'd managed to miss that all these months.