Security Update for That Malware Issue

"Mac Security Update 2011-003 has appeared in Software Update and is available for immediate download and installation."

You can read about it here, and download it here, but basically the update will search and remove the MacDefender virus and all variants. But it will also, according to the story, provide a "File Quarantine definition for the OSX.MacDefender.A malware and Mac OS X 10.6.7 will now automatically update the definitions on a daily basis."