Any chance we get seom sort of thread-support in *all* architectures
   somewhen?

It's worth noting that the JDK does not rely on the underlying system
supporting threads at all.  It originally shipped with its own user-level
thread implementation (Green threads), and has been ported to others.

That said, it would be nice if some of the pthreads work was folded into
libc.  Chris Provenzano (the author of the pthreads library) is working
on this.