Oh, finally. Apple adds Java 6 support for OS X Leopard. I’ve been delaying taking the plunge to Leopard because I want Java 6. (Seriously, you should see the number of times “When is Java 6 coming for Leopard?” threads go around on the Apple Java Developers’ mailing list).
The Mac implementation of Java has some really nice features — features that I wish the Java implementation on Windows had. You can make apps behave like apps. There’s a simple way to associate a Java app with file extensions (with icons!), and you can even double click a file to open it with your Java app. You can even open the file in an already-running instance of your app with little difficulty.