While I've haven't been a big fan of Senator Clinton's, I did understand some of the angst that her supporters felt after her lost. If Senator Obama lost, I would have been heartbroken. But I find it difficult to believe, especially if recent polls are accurate, that many of her most ardent supporters would support McCain over Obama because of some imagined endorsed sexism on the part of the Obama campaign. Much of the angst in my opinion is being manufactured by aides who recognize that their proximity to power is over.
Many folks in Clinton's inner circle - Begala and Carville come to mind -depended on their proximity to the Clintons for their livelihood. Obama's ascent symbolizes their descent and they can't handle it. Begula, Carville and others won't be the media darlings any longer and their million dollar incomes may be affected.
Hillary would make a poor choice for VP. Her negatives are high and the only reason why she polled well toward the end of the primary is because her campaign was able to drive the narrative that sexism influenced the campaign into polling gold. Obama effectively stopped campaigning against her in March so her positives rose as a result.
In addition, despite the fantasies that are being spun by Clinton supporters, although many describe them as fighters, they never really won any battles unless you describe epic losses in the House and Senate after a 40-year run as success or maybe you believe that the impeachment saga was fun. Moreover, she doesn't really change the electoral map although I may grant her the addition of Arkansas. She would most likely add the addition of some older women that elude Obama but he has strong support of women already.
So, in my opinion, the only folks really pushing this Hillary as VP meme is her potentially out-of-work advisors and a few folks from those wacky, fringe groups like PUMA.