He then added, in response to a question, that if he were to lose a primary he would still seek re-election.
"I intend to be on the ballot in November," he declared. (Krechevsky)
...Well, given that he's stronger among Republicans and independents than Democrats, that isn't surprising.
ConnecticutBlog, My Left Nutmeg and Daily Kos all seem to think this points to Lieberman's fear that he could, in fact, lose the primary.
But how likely is it that he could lose? A Dkos commenter pointed to Larson's loss in 1994 as proof that party-backed candidates could be defeated by grassroots liberal organizing. In fact, Lamont (if it's him) would be going after essentially the same voters as Curry did.
Still, Larson wasn't particularly popular, and Curry had been running for more than a year before the primary that year. Lamont would be starting from zero against a well-known, apparently well-liked incumbent five months before the convention, and eight months before the primary. The odds are not good.
That isn't to say Lamont shouldn't run. He should. I don't agree with Scott McLean from Quinnipiac that it's hopeless to run against Lieberman. A significant minority of Democrats want an alternative to Lieberman, and dedicated minorities can, in fact, win primaries. Bad starting odds don't an impossible race make.
Krechevsky, David. "Lieberman says he's ready to fight for Senate seat." Waterbury Republican-American 11 January, 2006.