Oracle/Sun has released Java version 7, update 15. What happened to update 14? Anyway, the new version includes a batch of security and other bugfixes they wanted to release with the last batch, and which were originally scheduled for release today. Confused yet?
Since the new version is all about fixing the rather horrible Java security vulnerabilities that have been revealed in recent weeks, you should go ahead and install the update, if you use Java. If you don’t use it, pat yourself on the back and count yourself lucky.
If you read the announcement linked above, you’ll notice that once again, determining the version being discussed is left as an exercise for the reader, since the version (7u15) is not mentioned anywhere on the page. There are plenty of references to the versions being replaced, which only adds to the confusion. Annoying.