windows 7Follow

Typical example of an improvement in Windows 7:

Need to maximize a window? Drag it to the top of the screen.
Need to compare two windows side by side? Drag one to the left side of the screen and one to the right. Windows 7 will size them equally and automatically.

Much of this kind of thing is possible in XP, but with many more clicks or keypresses. Windows 7 features several usability enhancements of this nature. Here's a video showing some of them...

http://www.metacafe.com/watch/2327389/ui_enhancements_windows_7/

If by workspaces, you mean virtual desktops, then no, MS still hasn't recovered the ball they dropped on that one.

Right now you're not missing anything, really.

But in about a year, when M$ drops their support for XP as planned, you'll miss the benefit of regular security updates. Eventually, hardware will cease to be made specifically for XP, and software will someday start requiring Vista or 7 to run.

This is a while down the road, of course, probably in the next 5 years, but there is a reason that no hardware or software today is designed to run on Windows 98 any more.