Fox and MSNBC have called it. And that AP call seems to have been withdrawn. (As if the political media needed yet another credibility hit.)
This is a nice boost for Obama, although I'm not sure it changes the basic CW coming out of tonight, as articulated by this AP headline: "Analysis: Clinton and Obama Start Anew."
Incidentally, I think Noam makes an interesting point below about how Obama might have been victimized by inflated exit-poll-based expectations. But this might be a case where Hillary suffers from the same dynamic, thanks to the drama of Obama's Missouri "comeback," which isn't an actual event.
Case in point: The Obama camp just issued a press release taunting the Clinton campaign for an earlier statement gloating that, despite being outspent and out-endorsed, "Hillary Clinton won this important toss-up state." Tomorrow's damage-control spin on this front should be pretty entertaining--and contorted.