It is entitled "Driftwood" and is at Milestone 3 which is fancy Longhorn jargon for version 3.
It is basically a mix between the Longhorn UIs and Vista's UI.
It combines Jade and Plex with Aero.
I haven't spent that much time on it though.
The theme features a unique start button, clear glass taskbar, and other goodies.
I lost the original versions (M1 & M2) when my HDD was accidently formatted, because this hack is really unstable...
Milestone 3 is not exactly the same as the other versions, as it was built from scratch.
You will need to either use a utility, or follow my system file patching instructions (found in Guides).
To install, navigate to %SystemRoot%\Windows\Resources\Themes\Aero, and take ownership of aero.msstyles.
Rename aero.msstyles to aero.msstyles.bak, and place Driftwood file in directory.
Reboot, and be greeted with Driftwood.
Screenshots:






Download:
Here