Nice experiment and a huge undertaking, do you already support the current implementation of java.util.concurrent? (requires atomic CAS through sun.misc.Unsafe and ability to park threads)
We are planning to update the demo (and perhaps post on HN) once I fix some IE issues (since we strive to be compatible with IE9).
Granted, it's possible that it invokes a native function somewhere deep inside itself that we don't implement yet, but fixing those are usually very simple.