It is likely that some of each VMs design decisions are so fundamental that it precludes an incremental migration of pieces from one to the other.
If there is insanely great stuff in the intersection you mention, it probably constitutes a research project, which it would make sense to undertake in the background (if at all). For Oracle, the only "insanely great" that counts is that which yields benefits that customers will pay for now/soon - not what's technically impressive. They're a sort of microsoft-research anti-particle. disclaimer I actually have no idea.