I'll be honest with you, with Visual Studio 2010 Premium or Ultimate and, TFS on top there really is an enormous amount of value (tech-wise). I know there is a financial incentive (and technological one) to keep innovating on Microsoft's part, but can you keep up?

Don't get me wrong in .NET 4.0 being a lifesaver, especially the innovation in WCF that rescued me on a highly distributed application I was working on, and the tidy up in WPF, but there is an enormous amout of work that has gone into the parallel platform, and testing, and debugging, and the team features in TFS, I think I may well decide not to move on, because a lot of the innovation in Visual Studio goes to waste. The Longhorn era has now instilled an agile ethos which is good, but you need to give us time to really appreciate the technology and build mature systems that are now possible.