Late last week Apple made an update to Mac OS X Snow Leopard available via the built-in Software Update facility. The update which brings Snow Leopard to build 10A394, is described as bringing “general operating system fixes for stability, compatibility and security.”
Mac OS X Snow Leopard
Despite Apple’s loose description the latest update to Snow Leopard brings along the Dock Exposé functionality demonstrated during the WWDC 2009 keynote.