Apple Java for OS X 10.5 Update 4 on Software Update
They have updated Java again, once again, it's an across-the-board update:
Java for Mac OS X 10.5 Update 4 delivers improved reliability, security, and compatibility for Java SE 6, J2SE 5.0 and J2SE 1.4.2 on Mac OS X 10.5.7 and later.
This release updates Java SE 6 to version 1.6.0_13, J2SE 5.0 to version 1.5.0_19, and J2SE 1.4.2 to 1.4.2_21.
So we're at pretty up-to-date versions of Java for OS X. Not bad. It's no surprise that we're lagging behind the Sun JDKs - Apple has never really pushed the envelope on JDK releases. But it's nice to be up to date just in case.