My bet is that the 160GB portable hard drives they are handing out to distribute preview bits will actually contain Virtual PC images of Windows 7 in various states or configurations. Such a setup will be more convenient to try, even if it does narrow what aspects of the OS can be seen.
In any case, Microsoft would do well to pay attention to the feedback it receives from these developers.
We know all of the reasons why geeks can make poor proxies for "real end users." Nonetheless, I recall the 2005 PDC, when Microsoft gave us the latest beta of Windows Vista. A chorus of complaints arose from many who tried the new OS. It's way too slow; it doesn't work with the hardware we have; we can't explain the 10-odd different SKUs to our customers.
Do these sound familiar? They should, because they're uncannily similar to the problems "real end users" found -- and continue to find -- with Vista.
At the time, the 'softies at the conference, who are generally open, approachable, and humble with regard to technical matters, didn't want to hear these complaints about Vista. I was rebuffed more than once: the SKUs haven't been ironed out yet; the beta build is a checked debug build, so of course it's slower. Well, maybe. But I found it to be little slower than the release build on the same hardware. Either way it was unusable.
I think everyone's learned from the Vista experience -- and that includes Microsoft, ISVs, consumers, PC builders ... and Apple.
Let's try it differently this time around, starting with feedback from PDC.
One last thing: it would make sense to release the Windows 7 preview to the general public at the same time. Why? It'll be on the file-sharing networks instantly, where there is a greater chance of folks downloading a trojaned image, etc. So it will help everyone to have an official distro from Redmond instead.