Apple has released new versions of the Java run-time software for Mac OS X. As Mac users probably know, Apple packages and releases its own Java updates, which means there is typically a delay between the availability of a new version (for Windows, Linux and UNIX) from Oracle, and the release of Apple’s version. This new release from Apple corresponds to Java version 6 update 29, released by Oracle in October. This release fixes a number of security flaws, some of them serious. More details are available in the security bulletin. There are actually two new Apple versions: Java for Mac OS X 10.6 Update 6, and Java for Mac OS X 10.7 Lion Update 1.
If you have Java installed on your system, I recommend that you update to the relevant new version as soon as you conveniently can. You can use the built-in Software Update mechanism, or you can get the new version from the Apple Downloads page.