Mac OS X Lion may be on the horizon, but Apple just released another update for Snow Leopard users that prepares them for 10.7, specifically regarding enhancements to the Mac App Store.
It also contains a number of bug fixes for Preview, iCal, TextEdit and more. Weblog TUAW has even discovered that the new update improved graphics performance on a number of machines, though Apple hasn't officially come out and included that in its update notes. Head on over to Apple's official page to read more, or go to the Apple menu and hit Software Update to download it. [Apple Knowledge Base]