As always, don't listen to conservatives proffering advice, as people like Brooks had absolutely nothing to do with your victory.
And, honestly, what's sadder than a conservative babbling about how this is all "a win for the centrists", in a desperate attempt to try to save the ideology that is his bread and butter?
Yes, some conservative Dems won. No, it wasn't all conservatives, and some were pretty damned liberal. Yes, Lieberman won. No, Lieberman's victory wasn't a victory against Kos. it was an embrace of the Republican party without the "R" to bring him down.
Hell, Brooks (along with many other pundits) doesn't even get that Kos doesn't care about ideology, and never has. He just dislikes Lieberman because he takes shots at his own party to get ahead. It works for Joe, but harms the party, and thus can't be held up as an example to Dems pretty much by definition.
I'm quite aware that this whole thing is just a way of setting the groundwork for battering Democrats as "out of the mainstream" again when the actually try to get something done. It was inevitable, and all things considered, it's pretty weak.
I just hope Nancy and Harry know it as well.