SmartOS (based on IllumOS) released - with KVM

Ah, I assumed you were talking about releasing the code under GPL, not about making CDDL GPL-compatible. But again - the only way to make CDDL GPL-compatible would be to make it a subset of GPL, it couldn't include the nice patent protection it has now, for example.

As for binary modules - yes, they are a problem, but it's just an annoyance. Releasing the code under GPL instead of CDDL would make it impossible to e.g. include DTrace in OSX - not "inconvenient", but just impossible, at least according to Stallman's interpretation of GPL.