Will Lieberman speak at the Republican convention this year? Will he reprise Zell Miller's role as Judas? Almost certainly.
It's a huge gamble for Lieberman, and it's hard to see what he gains from his increasingly erratic behavior. The Democratic Party needed Lieberman in its caucus in order to claim a majority in January 2007. If current electoral trends hold, the Democratic Party is likely to pick up four to seven seats in the U.S. Senate. If the Republican Party suffers a really serious collapse, the Democrats could pick up as many as ten seats. All of this means one thing: in January 2009, the Democratic Party will have no use for Joe Lieberman.
Lieberman is clearly angling for a cabinet post with a McCain administration. Whether or not Democrats win the presidency, they will almost certainly increase their majority in the Senate to such a degree that they will no longer need to cater to Lieberman.
If Barack Obama wins the presidency, then Lieberman is screwed. He will be stripped of any committee appointments or privileges he may now enjoy as a Democrat. He could try to join the Republican Party, but its doubtful he'd be welcome there: Lieberman is liberal on a range of issues and really only agrees with the Republicans on a single issue--the War in Iraq.
Things are about to become very lonely for Joe Lieberman.