Mac OS X and Virtual Desktop Functionality?
Appleinsider claims that Apple will be building in Virtual Desktop support into Mac OS X in 2004.
Appleinsider points to an Expos hack that shrinks all windows into a small window as evidence of ongoing work on this feature.
"Virtual Desktops" is a feature that was popularized in Unix windows managers, allowing users to invoke any number of virtual screens for improved window management. CodeTek currently offers a trialware application called VirtualDesktop which implements this functionality on Mac OS X.
Another curious Mac OS X Expos hack is described here -- the Expos "blob".
Update: Reportedly, the "blob" hack was simply an early way to activate Expos during developer testing.