I've been much more sympathetic to Lieberman's campaign than to Lamont's campaign. From a progressive point of view, I think the money that Lamont will require to win a general election could be better spent helping someone like Sherrod Brown win in Ohio (not to mention helping us keep the Maryland seat, where a Nader aide is trying to be a spoiler.)
I don't mind Lieberman's disagreements with the Democratic leadership the few times there are disagreements. I happen to think a party is less likely to become as corrupt as the current GOP and more effective if there are some internal debates. But Lieberman's decision to ignore the results of the Democratic Party is pretty shameless.
If Lieberman would spend more time running a campaign, he wouldn't be in the trouble he's in. It doesn't even look like he's running a campaign. Declaring he won't listen to the results of the Dem primary makes the Party look less united than it really is. Given the media's propensity to greatly exaggerate any difference among Democrats, Liebermans ploy only helps perpetuate a false perception. He should know better. And he should have been running a better campaign.