Since I'm a dum guy and don't know how OS's work, I will list some things dum guys can appreciate 'bout Win 7, and then some things I don't so much like about it.
1. You can set an entire folder (like maybe your folder of Firefly pics) as a desktop background, select the pictures you want to use, and set it to rotate through that set of pictures at your desired interval. Also, you can save different "themes," that determine the look of your desktop, cursors and screen saver.
2. Desktop images look much more clear and rich, or at least they seem to.
3. You can move your toolbar to the top, bottom or side of your screen. I like the top, although there is a problem with the tops of windows getting trapped back there.
4. It has a built-in desktop gadget for CPU/RAM usage and Weather.
5. The shut-down button just gets better as you move from 2000 to XP to 7. Maybe. I like that I can shut down with one click on the start menu, but it might be a little too easy to shut down by mistake.
Things I don't like as much.
1. When you save downloads to your desktop, they don't actually show up on the desktop. They end up on a list that is labeled "Desktop," which is not the actual desktop.
2. I don't like that it's harder to edit the menu options for multi-boot. In XP, you can simply edit the file from System Properties. With 7, I had to run command prompt as administrator and open bcdedit, then use google to find out what commands to use. Or maybe I'm too picky about what my menu says.