Evidently he thinks he’ll control the questions:

“I’m not into the small bore stuff. I don’t care whether or not she built a bridge to nowhere. I don’t care if she sold a plane,” Biden said at the first event. “What I care about is what in God’s name is she going to do – along with John McCain – about the thousands of people who don’t have health care,” those struggling with other economic problems, and the foreign policy challenges facing the country, Biden said.
“What I’m going to try to do, what I’m going to try to do very hard is to focus on the issues,” Biden said.
“Folks look, I know what she’s going to try to do. She’s going to try to make it as personal as she can. She’s going to take a lot of straight lefts and jabs at me, she’s going to try to get me to respond, she’s going to try to get me to respond in a personal way. That’s not my style. I’m not going to do it.”
He added that Gov. Granholm of Michigan has agreed to spend four days with him to help prepare for the Oct. 8 VP debate.

If she’s such a rube for the backwoods of America like the Democrats and MSM (I know, that’s redundant) are portraying her, then why does he need four days to prepare for the debate? He should be able to handle her, he has a superior IQ, doesn’t he? Maybe they’re disciplining him not to say anything sexist or condescending.
I think it’s clear that he’s rattled.