In the first poll released on a possible Weicker/Lieberman rematch, Weicker badly trails Lieberman 32% to 54%. Rasmussen Poll here.
However, Weicker's strongest support comes from liberals and Democrats. 37% of Democrats would vote for Weicker. The group in which Weicker comes closest to Lieberman is among self-described liberals, where Weicker trails the senator 40-44. Lieberman's strongest support comes from self-described conservatives, 62% of whom would vote for him instead of Weicker.
This sets up the intriguing possibility, suggested by Chris MC, of a three way race in which Weicker as an independent (he's not running as a Democrat) takes the liberal vote and a Republican candidate could take the conservative vote. Where does that leave Lieberman?
Lieberman's last two Republican opponents were nobodies, but each got around 34% of the vote. Lieberman won with a combination of moderate unafilliated voters and Democrats. What if the liberals in that group split off? If Weicker's numbers held in the 30s, and the Republican candidate got as much as the Republican candidate often does (30%-35%), then the race suddenly becomes one of the closest in the nation.
Republicans have promised a candidate. If Weicker does decide to run (and he has kind of boxed himself in, here, by saying that he would stay in if a credible anti-war candidate didn't appear), then we have a very interesting race brewing.