If you ever wanted to buy a MSDN subscription, it is the best time to do it. If you buy any packages from “Visual Studio 2008 Professional with MSDN Premium” or better before March 22nd, 2010 and you will automatically be upgraded to a higher level when the packages containing Visual Studio 2010 will be released.
See all the details from http://www.microsoft.com/visualstudio/en-ca/products/msdn/default.mspx#roadmap