Nebraska "Democratic" Sen. Ben "Half" Nelson is retiring, according to reports. Half Nelson is one of the least reliable Senators as far as supporting the Dem agenda -- outgoing Sen. Joe Lieberliar (I-Party of One) and Sen. Mary Landrieu are others.
It's characteristic of a political hack like Half Nelson to quit when facing a tough election year, and leave his nominal Party in the lurch when it comes to holding the Senate majority. Nice timing. While his seat will likely go Rethuglican, it won't be hard to miss him and his frequent alignment with Rethugs.
UPDATE: One bright spot is that former Sen. Bob Kerrey is being talked up as a possible candidate with a chance to hold the seat for the Democrats.