It's about the applications. And since we don't have many of those yet, it's hard to see the advantage. But make no mistake, Windows Presentation Foundation is a powerful reason to prefer Vista.

Vista's upgraded user interface

The Aero user interface is a minimalist showcase of some of the things application makers might take advantage of with WPF. It appears that Microsoft purposely held back its designers to keep from turning the operating system into a theme park. The use of transparency in Windows Sidebar, though, gives you some insight into what might be possible. Windows Explorer's scaling icons are another hint. The Windows Photo Gallery is an excellent tool for managing images, due in large measure to the power of WPF.

Transparency opens up a cluttered desktop. HGTV addicts will note that it's the same idea as adding a mirror, windows, or a skylight to a room. There's nothing like that annoying feeling of trying to find another app window amidst the mess of 20 open windows. And yet many power users work that way.

Microsoft's use of transparency in Vista is subtle, not glaringly obvious. It isn't so much something you see when you look at Vista -- it's something you feel when you use it. The more aesthetically oriented you are, the more you feel it. It's the back-of-the-mind knowledge that does the trick. You know that window is there in the back. You can see it. It's not lost.