I downloaded and installed Windows 7 Beta on my Ubuntu desktop (Core 2 Duo, 2GB RAM) using VirtualBox. I gave it 1 GB of RAM. The install went smoothly and I am quite happy with the results. I haven’t used Vista much but I have heard that it is quite sluggish. Windows 7 Beta is quite responsive and is very pleasing to the eye.
Microsoft has done a good job. However, the fact remains that it released a product (Vista) and waited for a couple of years for Moore’s law to catch up and make it look good.