With Obama having won 11 states in a row, many bloggers were all but calling the race for him, and some Democrats were calling for Clinton to step down to help build party unity. But Obama never had more than a handful more delegates than Clinton. According to CNN's count, count, he still does, even after Clinton's victories last night, but it's still neck-and-neck. The magic number for the nomination is 2,025 delegates: Clinton has 1365 to Obama's 1451. Mathematically, she's still in the hunt.
More importantly, she may have stopped the aura of inevitability the media (dear god, the media!) creates anytime someone goes on a win streak. I've said elsewhere that it's too soon to call the victor. Obama's mixed-message on NAFTA could hurt him. He keeps (foolishly) bashing it to the public, but it has been reported that his campaign had advised Canadian Ambassador Michael Wilson that Obama supported NAFTA. What Obama can't afford now is questions about his integrity--his appearance of integrity is his strength in this campaign. If that slips, Clinton is right behind (as odd as that sounds, since fewer people would rate her as highly on integrity).
Only a true gambler would wage money on the outcome right now. Speaking purely as a professional political scientist, I'd love to see it go to the convention. My colleagues who study campaigns and electios would have a field day. And while DNC Chair Howard Dean openly worries that a divided convention would make the Democrats look bad, it would also draw vast amounts of attention from the public, and the traditional post-convention bounce--provided the Dems end it on the right note, and keep the nasty bickering in the back rooms--could be huge for them, making the general election campaign an uphill battle for MCCain.