The first Windows Vista beta version focuses greatly on security and has many enhancements to protect the user's computer. It also incorporates a beta version of Internet Explorer 7 and new features to improve PC management and performance.
Additionally, the beta 1 version also includes user-interface improvements.
Here's a screenshot showing the new Virtual Folders technology, which is a saved search that is automatically and instantly run when a user opens the folder.
A full fact sheet of Windows Vista can be found here and some more Vista screenshots can be seen over here.
It looks like Microsoft is aiming at lots of media attention with this beta release
Microsoft announced Windows Vista beta 1 is now also available for MSDN subscribers.