Visual Studio 2008 Shell is a new Microsoft product (to be released) based on Visual Studio 2008. Maybe something for Autodesk to make use of instead of the old VLIDE (that is not improved much) and VBAIDE.
"The Visual Studio Shell accelerates development by providing a base integrated development environment that can host custom tools and programming languages."
This means that AutoLISP could be added to this environment.
"Created in response to requests from our partners" - Maybe Autodesk already is working on this...