I think it would be a chessmaster move if Sun develop and provide a JVM that runs inside .NET CLI (Common Language Infrastructure).
Such VM could use some features of .NET, such as the Jitter and the Garbage Collector.
A more agressive move would make Java use COM+ in the RMI/JNDI implementation, use GDI+ for Swing implementation, and perhaps use ASP.NET for JavaServer Faces implementation.
This would prove the world that Java is defenitily a platform independent language, and that who choose J2EE automatically have their systems running on and using features of .NET platform.
the current jvm already have a jit ( hotspot ) and a garbage collector. The jit and the gc is more mature than the .net version.
Using everything you said wont prove than java is platform independent but prove than java need to use competitor product to work.