I don't think any skinning engine for Windows XP and lower supports skins with transparency/blurring like the one in Vista.
Windows 1.0 had some kind of taskbar (a kind of green area at the bottom of the screen that could only be covered by maxmized windows), but they removed it in Windows 2.0, then it reappeared in Windows 95, with 16x16 icons and the clock displayed by default (you needed to edit manually the win.ini in windows 1.0 to have the clock enabled at each startup).
Everybody thinks Apple invented the GUI, but Xerox had one years before. With Windows, trash cans, and all that stuff.
Anyway, I'll not switch to Vista. I know a guy who used Longhorn as his main OS. Of course he didn't backup what was on his drive, so just too bad....
Introducing Windows 95.
It has a trash can you can open and take things back out of again.