Apple in its release notes for Java for Mac OS X 10.6 Update 3 stated that Apple’s own port of Java runtime is no longer maintained. Apple likely will remove its own Java runtime in Mac OS X Lion.
This means that the Apple-produced runtime will not be maintained at the same level, and may be removed from future versions of Mac OS X. The Java runtime shipping in Mac OS X 10.6 Snow Leopard, and Mac OS X 10.5 Leopard, will continue to be supported and maintained through the standard support cycles of those products.
Apple ported its own Java runtime for a better integration with OS X user interface elements. The runtime is shipped with Leopard and Snow Leopard. By not maintaining its own Java runtime, Mac users has to rely on official Java runtime by Oracle. Java application will not look as Mac like using non-Apple Java runtime. Using official Oracle Java runtime will save Apple from Java security blame as it is no longer responsible for Oracle’s software defects.