Apple has released Java for Mac OS X Upgrade 2.
Java for Mac OS X 10.6 Update 2 delivers improved compatibility, security, and reliability by updating Java SE 6 to 1.6.0_20.
For more details on this update, please visit this website:http://support.apple.com/kb/HT4141 
For information on the security content of this update, please visit this website:http://support.apple.com/kb/HT1222
This update is available to install via the OS X Software update mechanism and brings Java on the Mac to the same version as on other platforms, 1.6.0_20.