Videos demonstrating what's believed to be a future build of Android have been leaked, courtesy of Haykuro of the xdadevelopers forum. The videos, which you can see below, show a new, advanced Android desktop with more widgets and a streamlined GUI.
The new build is believed to have been taken from a new HTC device, possibly the Hero, and developed by a team of Android fans. Earlier this week, a video of a Hero build running on a T-Mobile G1 was published.
It's unclear when the new firmware - which seems to be going by the codename Rosie - will be released. More screenshots here.