Longhorn News From WinHEC
The WinHEC Longhorn alpha is already up in MSDN Subscribers download, which is accessible for MSDN Universal subscribers.
Apparently, one of the highlights of Longhorn, the Desktop Composition Engine (now called Desktop Windows Manager) is actually in the WinHEC build, but it is currently turned off. The guys at Neowin have enabled it by invoking "c:\windows\i386\sbctl.exe" and included several screen shots and videos here. The shadows give windows a nice 3D feels; also alt-tabbing now applies a 3D transform.