Let him go. If he wants to bet on the GOP re-taking control of the Senate in 2008 — well, good luck with that. The only practical result would be that he would lose his chairmanship, and he’s doing a bad job of that anyway.
There would be no power change ala 2001. That flip was only possible because of a compromise deal made in January of 2001. When the Senate first met to establish rules for that session, the Dems technically had a majority because Al Gore was still the President of the Senate. The deal was, equal representation on committees, various other concessions, and an out clause that if any seat flipped from the GOP to Dem caucus the dems could re-take control of the committees and rules process. Which then happened.