I try not to do this too much, but wanted to make sure you folks saw a couple of posts that were especially relevant.
Visual Studio Team System 2010 Development Edition
Brian Harry just posted about the Visual Studio Team System 2010 Development Edition that you've gotta check out. He points out a few of the critical new features in the product that you can check out in the current beta 1 bits. Check that post out here.
DSL Tools Modelbus Sample
Jean-Marc, a fantastic Program Manager on my team, has recently published a sample that shows how to take advantage of the new functionality the DSL team has made available in the recent release of the DSL SDK 2010 Beta1. The sample demonstrates the use of the Modelbus, which is a new technology that enables sharing between disparate DSLs.