Windows 8 was presented at the BUILD conference and a preview was available for download.
You can find the iso (with or without tools) here : .
I couldn’t get it to work in VMWare but it works well in VirtualBox.

There are several new things :
- Integration with Windows Live (you can put your Live mail and it will connect)

- Metro interface (my WLM picture appeared a bit later)

- Ribbons in explorer (you can go to the usual interface using the Desktop button or Windows Explorer button on the previous screen)

- A neat task manager (you can go back to the metro interface with the windows button in the bottom left)

- IE 10