This has been all over the blogs, but has it been picked up by the real press in Michigan?
Given the Republican history of screwing around in Michigan (to the benefit of their soulmate, George Wallace, for example), and the fact that Michigan has a sizable crew of angry unemployed folks, it could conceivably catch on. But if it's just Kos and the bloggers, well, that might have some small influence in Ann Arbor.
But Kos should be careful what he wishes for. I don't think anyone can predict what is going on well enough to know whether Romney votes will help or hurt the Rs as a whole.