I took the plunge last weekend and installed Windows 7 on my primary home machine. Slightly risky, but I figured since it was good enough for many others, it wasn't too big a risk.
Basically, Windows 7 feels like Windows Vista, but polished. It's all the little things that make a difference.
One of the big differences, though, is the revamp of the taskbar - while you can change it if you choose, the default presentation is icon based, not named.
I like it - a lot.