Harry Reid is calling Joe Lieberman in to have a little chat. Expect at a minimum for him to lose his chairmanship of the Homeland Security Committee, and for him to be ineligible for any leadership positions in the Democratic caucus.
This leaves Lieberman with the worst of both worlds. If he stays with the Democrats, he will be in the majority but won’t have any input in shaping the agenda someone of his seniority normally would. If he defects to the Republicans, he will be in the minority, where he will probably have even less influence, and in all likelihood would not even get vicechairman status on a Senate subcomittee.