PC Magazine has posted their hands-on experience with Microsoft's Windows Vista, BETA 1:

After several years of waiting to see the successor to Windows XP, code-named Longhorn, we've finally gotten our hands on Beta 1 of what now will be called Windows Vista.

This version, aimed at developers and IT shops, lacks many features that the final Windows Vista, still over a year away, will have. But it has all the basic foundations of the OS and displays Microsoft's new emphasis on making a system that will be more stable and secure, as well as giving users greater clarity as regards their files. This "clear vision" is what Microsoft says is reflected in the Vista name.

The early version of Beta 1 we tested shows a focus on the basic structure of the operating system—in particular, a lot of changes to the things that users don't think about that often but that turn out to be very important. When Chris Jones, VP of the Windows Client team at Microsoft, discusses the team's goals, he talks first about efficiency and reducing the number of defects; then about increasing the "confidence" people have in their PCs (including better security); and lastly about improvements to user experiences, such as changes to the user interface.

These goals are evident in Beta 1. The device driver model has been reengineered for increased simplicity and security, so hardware that takes advantage of it should be more stable. (You'll still be able to run XP devices for compatibility, though).