Gareth provides some of the reasoning behind this move. Here's a bit more.
One of the most innovative aspects of DSL Tools is the model-driven approach we take to building a graphical designer which brings the cost of creating such tools to the point where it is cost-effective to invest in building the tools within the first project that they are used. This move opens up the opportunity to broaden this approach to creating other kinds of Visual Studio Extensions. I'm looking forward to the challenge, and to mark this broadening of focus, I've provided a new one-liner to describe my blog: tools to build tools. If you have ideas of software development tools you'd like to be able to build on top of Visual Studio then I'd love to hear from you. Just send email or add a comment.
The move also makes it easier for us to exploit the new VS2008 shell, in providing a way to deliver DSL-based tooling to folks involved in software development who are not in the engineering role, and so don't need or want all the capabilities that Visual Studio has to offer. This has been requested over and over by customers, and it's great that we'll now be able to address that need.
And, of course, we'll be using DSL Tools ourselves to build the VSX authoring tools: there's nothing like dogfooding your own stuff to drive improvements!
I'm also pleased that I still get to work with friends in Team Architect albeit in a different capacity: they are building some exciting products using DSL Tools, and we'll be making some enhancements to help them. Watch this space.