64-bit Java 6 была давно уже, а вот 32-bit версию Apple затянули до этого момента. Причём неизвестно почему, ведь Apple Java базируется на Sun HotSpot.
Java applications only launch in Java SE 6.
Description:
Since Java SE 6 is the only Java version shipped with Mac OS X 10.6 Snow Leopard, any application that requests an older version of Java will only launch in Java SE 6. No dialog is presented, since there is only one choice, and the app will either work correctly or it won't.
Workaround:
Ensure your application will run correctly on Java SE 6, and express that in your app's Info.plist or JNLP (use 1.4+, 1.5+, etc).
32-bit Java 6 для Mac