Unlike Fred Thompson, Joe Lieberman's speech was a flashback to his wan 2004 presidential campaign performance. His sad-sack demeanor is just not suited for convention hall applause lines, and you occasionally got the feeling that the audience didn't really get his jokes (e.g. when Lieberman said "if John McCain is just another partisan Republican, then I'm Michael Moore’s favorite Democrat," and felt the need to add, "[a]nd I'm not.")
Also, if Lieberman is so fixated with putting country over partisanship, why doesn't he just fight to create a bona fide third party?
Finally, it's a bit weird that Lieberman devoted several lines to the excellence of Sarah Palin but never once mentioned Iran.