Just found out that one of the frequently-heard requests for Team Foundation Server, namely integrated support for Visual Studio .NET 2003, will be granted. We'll be providing basic integrated version control for Visual Studio .NET 2003 shortly after launch as well as integration with Visual Studio 6.0, which will be available at launch. So while you're trucking ahead with Visual Studio 2005 for your new projects, you can still take advantage of the robust and powerful features of Team Foundation Server for your older code.
I like being able to say "yes, we'll support that". :-)