Changes from vista (in a nutshell):
- Vastly improved performance in all sorts of areas (start-up/shutdown, application loads etc.)
- New taskbar/start menu- really efficient if you embrace it
- Jump menus (part of the change noted above)
- Libraries- lets you organise folders from all over your hard disk into consolidated folders (sounds random, but very handy)
- Aero peek- really slick previews of open windows
- Improved wireless/power options
- UAC less irritating
- Support for various new hardware technologies
- New devices and printers section, with 'device experiences' (fancy name for pictures of your devices, but hey- it's cool)
- IE 8 (not a change I care about particularly...)
- Less crap bundled with windows
- Aero snap- windows automatically resize when you point them at the edges of the screen = slick.
- New keyboard shortcuts and improved multi-display support
- Too much more to list here. Just search for 'windows 7 new features', and you'll see plenty more

