Visual Studio 2008 Product Comparison Data Sheet
Microsoft has compiled a very nice product comparison data sheet for Visual Studio 2008.
Overview (from download site)
This data sheet provides a comprehensive product comparison of the Visual Studio 2008 IDE products. It does not provide data about Visual Studio Team System 2008 Team Foundation Server, Visual Studio Team System 2008 Team Explorer, or Visual Studio Team System 2008 Test Load Agent. This data sheet is provided for illustrative purposes only.
Get it here.