Apple has pushed out the Mac OS X 10.6.6 update and is available to download now. Mac OS X 10.6.6 update comes with many fixes and improvements in the software. A major attraction, the Mac App Store has also been launched through this update. You could update to Mac OS X 10.6.6 using Snow Leopard’s software update or download and install it from the below link.
The official description for Mac OS X 10.6.6 are as follows :
The Mac OS X 10.6.6 Update is recommended for all users running Mac OS X Snow Leopard and includes general operating system fixes that enhance the stability, compatibility, and security of your Mac. It also includes the Mac App Store, the best way to discover and buy new apps for your Mac. The Mac App Store, a new application you’ll find in the Dock, includes the following features:
Discover Mac apps: Browse featured apps, top charts, and categories, or search for something specific. Read detailed app descriptions and user reviews, and flip through screen shots.
Buy and install: Easily purchase apps with your iTunes account. Apps install in one step and are quickly available from the Dock.
App updates: The Mac App Store keeps track of all your purchased apps and notifies you when free updates are available.
Get more info on the topic from here
Download Mac OS X 10.6.6 (Combo) from here