Lots of VERY cool new features, for example:
- Anti-Virus out the box
- Hyper-V on the desktop
- Finally a multi-montior taskbar
- LiveID & Syncing
- Remote file access through firewall e.g. access work PC from home
However, I'm under no illusion that this is still Pre-Beta so subject to change and bugs.
*Update 14/09/11 * - Helps if I read the last slide of the keynote, the downloads were available as of 3am GMT. I've downloaded them now and installation is under way.
Another feature I forgot to mention that has been a long time coming, built in ISO & VHD mounting.