The respected Cook Political report writes:
It is increasingly clear to both independent analysts and Democratic leaders that Dodd is just too badly damaged to have a decent shot at getting re-elected, almost regardless of who wins the Republican nomination. Democrats have given Dodd time to attempt to repair his problems, but nothing appears to have helped enough to salvage his position.
And meanwhile, Jim Geraghty says he's hearing that Democrats are getting antsy:
In a very short time – just the past few days – I've heard a dramatic increase in the amount of talk about Sen. Chris Dodd being talked out of running for another term, and having some other Connecticut Democrat run for his seat, perhaps State Attorney General Dick Blumenthal or Rep. Chris Murphy.