http://mail.openjdk.java.net/pipermail/macosx-port-dev/2014-February/006388.html

Remove the “system” JVM installed and maintained by Software Update
% sudo rm -rf /System/Library/Java/JavaVirtualMachines/1.6.0.jdk

Remove any Java Developer Previews
% sudo rm -rf /Library/Java/JavaVirtualMachines/1.6.0*.jdk

http://mail.openjdk.java.net/pipermail/macosx-port-dev/2014-February/006388.html