I am always surprised to find out how many people DON'T KNOW about the MSDN Virtual Labs. With Virtual Labs, you can "Quickly evaluate or learn how to build great applications for Windows and the Web through a series of guided, hands-on labs which can be completed in 90 minutes or less. The best part is, the MSDN Virtual Labs don’t require any installation and are available to you immediately for FREE."
These are a great resource for those of you who don't have the time or ability to install a bunch of software just to do an evaluation. You do have to install a browser plug in.
There are already a few .NET Framework 3.0 labs as well.