I am running Windows 8 build 7955.
It still looks like Windows 7, but there are some new features most notably the ribbon UI for windows explorer.
The details pane is on the right and vertical same as preview pane so it's either-either situation, but I don;t think I can get used to vertical details pane.
The status bar is back on the bottom. Do we need it? Who knows.
Also the user account settings and icon on the right of the taskbar are new. Which seems nice.
Then the pattern login is new which is intended for tablets and touch devices, but you can use it on desktops also.
The task manager is quite different but I am not sure if it's for the better.
There's an integrated pdf reader called Modern Reader.
The most interesting thing though would be the fact that there's no more BSOD, now it's.... well still BSOD but it's BLACK. I don't have a screenshot of this. Sorry.And here's the video....
You can crab two windows 8 wallpapers here http://bit.ly/hqwalls8