It seems that the powers that be have decreed that this little joking exchange was The Moment of yesterday's debate:
Like Ed Kilgore, though, I felt that this wound up sort of missing the point. "In asking why Obama had so many Clinton administration advisors, she was presumably trying to say: Doesn't this show your inexperience?" I don't think that's right either, though. I think the question was actually meant to ask precisely what was asked -- superficially, there doesn't seem to be a lot to choose from between Bill Clinton's wife, with a team packed full of ex-Clinton people, and between a young Senator from Illinois with a team packed full of ex-Clinton people.
Obama chose to parry this with a solid joke, but as Brian Beutler says the real answer to the question is interesting and important. Bill Clinton was president for eight years and a ton of people worked for him over those years so it's no surprise at the end of the day that both campaigns have ex-Clinton people associated with them. But though there are various exceptions and ins-and-outs to this, the basic shape of things is that Hillary's team is weighted toward people who, like her, backed the war whereas Obama's team is weighted toward people who, like him, opposed it. Obama's standard has also attracted some prominent people like Zbigniew Brzezinksi and Samantha Power (both of whom opposed the war) who weren't in the Clinton administration.
Neither candidate has really tried to open up a broad doctrinal argument, but within the wonk world, in short, there's a significant divide that's reflected in the Clinton versus Obama race. And while this was most notably operationalized over the Iraq question, it reflects some broader differences -- Obama people are more likely to value international law, strategic restraint, and a narrow focus on al-Qaeda whereas Clinton people are more likely to take a pragmatic/instrumental view of international institutions, worry that nothing will happen without American leadership, and to have more sympathy for the Bushian idea that you need broad confrontation with rogue regimes. What's more, you can see this reflected in the differences between the campaigns to some extent in things like Obama's promise to try for a "grand bargain" with Iran and a recommitment of the United States to the eventual elimination of nuclear weapons worldwide versus Clinton's tendency to gesture in those directions much more modestly.