Things that are different:
Dock style taskbar thingee, like you see in the Mac OSX. Windows always had such a contrivance but it seemed like an after thought relative to the design and the icons were dinky to account for screens not having a lot of landscape back in the day. New stuff is good stuff.
Loads quick. Maybe it's my MBP, but hot dang does Windows 7 pop up quick when I boot my machine. As quick or maybe quicker than Mac OSX. Baffling I know.
Has some functions I haven't seen before or played with. Looks like there's something like what the Mac has for taking screen shots of portions of the screen, and a few other little toys. I'll try em' out later.
Things that are the same:
The labyrinthine architecture of the OS is mostly the same. If you want to change a setting, it's 5-6 menus deep into the programming.
Internet Explorer is a worthless and frustrating to use browser. Always has been, probably always will be. (Sad face)
Same lack of out-of-the-box usability. It has the usual programs you'll never use and look for free or cheap versions online.