Java for Mac OS X 10.7 Update 1 and Java for Mac OS X 10.6 Update 6
Apple has released Java for Mac OS X 10.7 Update 1 and Java for Mac OS X 10.6 Update 6. In both cases, the updates address about a dozen security vulnerabilities, including one that could allow an untrusted Java applet to execute arbitrary code outside of the Java sandbox. (Free, 62.53 MB and 75.45 MB)
Unfortunately the Java for Mac OS X 10.6 Update 6 won't install unless you're running 10.6.8.? I've never updated to 10.6.8 because of bugs in 10.6.8 and 10.6.8, I believe it also drops Rosetta?
Apple has addressed all the major problems that were introduced in 10.6.7 and 10.6.8 at this point, so that's not really an issue. And Rosetta disappears from 10.7 Lion, but is still present in 10.6.8 Snow Leopard, so that's not an issue either.
All that said, unless you actually use Java much, or run into Java on the Web a lot, this Java update probably isn't a really important thing to have.