Apple has released MacOSX 10.6.7 and Security Update 2011-001. This update is for server and client and includes over 50 fixes including security fixes for Safari, ImageIO, ATM, ClamAV, HFS, QuickLook and PHP. This update is mandatory is recommended to be installed, the update requires a reboot.
One interesting side note is that the File Quarantine now will flag OSX.OpinionSpy. This seems like an after thought and we recommend that users install a complete finished product such as Virus Barrier or Sophonos AntiVirus. Apple may decide to do something with this in the future or other developers but as it stands this feature does not provide adequate protection.