Set to ship roughly towards the start of 2007, Windows Vista will be Microsoft’s first major operating system release since introducing Windows XP in 2001. The new Windows Vista operating system offers a shiny new user interface, better security, improved data organization, and and a stupidly over the top but new look that is the Aero Theme, which gives your desktop a glass like look. It’s all very neat, but somewhat intensive on the user’s graphics card - so if you have an old machine (older then 2yrs) then you’re bang out of luck 
Anyway, Jake over at http://spikex.net/blog/ has a small but informative preview on Beta build 5308 of Vista. It’s a good read!