You'll also need to be running the latest version of Leopard, 10.5.2, in order to install the new(ish) Java hotness. The bad news is that Java SE 6 can only be installed on 64-bit Intel Macs, so anyone with a Core Duo or a PowerPC processor is out of luck. The update will leave Java 5 alone, and won't actually change the default version of Java to Java 6, but Leopard owners should now be able to take advantage of Java applications built for the newer version. The update adds support for the Java 6 Standard Edition (SE) to Leopard, and comes with Java SE 6 version 1.6.0_05.
Apple has finally gotten around to adding Java 6 to Leopard, though, and has released the new Java for Mac OS X 10.5 Update 1 with the new version. Sure, Apple did release a Developer Preview of the Java 6 JDK, but that wasn't an official consumer release. In fact, Java 6 was released in December 2006, but wasn't added to Tiger or Leopard in 2007. When it comes to Java 6, Apple's hasn't exactly been quick to add it to Mac OS X.
