Regular Expression Language Service
I've finally gotten around to posting the Regular Expression Language Service so you can get to it.
This is the project that I wrote during the TechEd VS Extensibility Feature Cookoff where I had to write this in 45 minutes or so. I tried the code with Whidbey Beta 1 and it worked for me.
One major point to remember here is that this is all managed code and really fairly easy to implement compared to working with Babel (native abstraction for language services) or native interfaces directly.
The project is on the workspaces on the GotDotNet site: http://workspaces.gotdotnet.com/RegExLangService