Washington Post columnist Kathleen Parker:

Well, darnit all, if that dadgum girl (wink, wink) didn't beat the tarnation out of Joe Biden. ... Palin is a populist pro. She hit all the notes that resonate with non-elite Americans: family (Hi Mom and Dad!), “Can I call ya Joe?” personal responsibility, Wall Street greed, children with special needs. Her most effective technique was speaking directly to the American people and letting Joe know that's what she was gonna do, doggonit. Stylistically, she used the language of the people to great effect. ... I'll have to go to the transcript to figure out what Palin actually said and try to figure out whose facts were right. But there's no question: She won the debate on popularity.

CBS:

Uncommitted voters who watched the vice presidential debate thought Democratic vice presidential nominee Joe Biden did the best job by a margin of more than two to one, according to a CBS News/Knowledge Networks poll taken immediately following the debate.

[...]

Forty-six percent of these uncommitted viewers said Biden won the debate Thursday night, while 21 percent said Palin won. Thirty-three percent thought it was a tie.

Even a quarter of Republican uncommitted voters thought Biden won the debate.

CNN:

A national poll of people who watched the vice presidential debate Thursday night suggests that Democratic Sen. Joe Biden won, but also says Republican Gov. Sarah Palin exceeded expectations.

The CNN/Opinion Research Corp. said 51 percent of those polled thought Biden did the best job, while 36 percent thought Palin did the best job.

[...]

Respondents thought Biden was better at expressing his views, giving him 52 percent to Palin's 36 percent.

On the question of the candidates' qualifications to assume the presidency, 87 percent of those polled said Biden is qualified and 42 percent said Palin is qualified.