To paraphrase the Simpsons: "Why now? Why not five years ago?"
Sure, he went to bat for ending DADT. But he also singlehandedly killed the Medicare extension and helped ruin the Dems' chances in 2010 by playing the Rotating Villain of the Week on health care. Connecticut could have had a REAL Dem in there years ago, had his ego not stood in the way. Oh, and he's part of the reason middle east policy is so screwed up, too.
No, there won't be a single tear shed in this corner of the Net over the retirement. Except that it took too goddamned long.