Here’s the deal
The Visual Studio product line-up is evolving in 2010. During this transition time, you have an opportunity to activate a MSDN Premium subscription, which will convert to a more advanced edition of Visual Studio 2010 with MSDN.
In other words, buy Visual Studio 2008 Team System with MSDN Premium now, and step-up to Visual Studio 2010 Ultimate with MSDN when it ships for no extra cost. It’s a huge costs saving over time plus you get Visual Studio 2010 Ultimate with MSDN as soon as Visual Studio 2010 Ultimate with MSDN ships.