Microsoft has released the next CTP of Visual Studio as a Virtual PC image. Weighing in at a whopping 3689.9 MB, this is by far the largest non-OS download Microsoft has ever offered.
Using Virtual PC for demos has several advantages over a traditional demo. First and foremost, there is no risk of "corrupting" ones production environment. Many pre-release demos have flaws that prevent them from being completely uninstalled and may cause problems long after the final version has been installed. By isolating it in a separate image, Microsoft has eliminated this issue.
Another advantage of the image is the vendor has a tighter grip over the environment. With the virtual image, Microsoft has ensured that all the prerequisites have been installed and no other beta software can interfere. But by the same token, the test is limited to just the demo environment. While this is acceptable when doing proof of concept tests, it won't work for beta and release candidate tests.
A more significant disadvantage is the sheer size of the image. Taking over 5 hours to download via T1 (and over a day using Cable/DSL), it is hard to see many people wanting to try it that badly. And of course, there is the overhead involved in installing Virtual PC in the first place.