I'm not the least bit surprised that McAuliffe, Ickes, and Wolfson are all asserting that Hillary Clinton won't concede tonight. I don't even buy the notion that she'll concede if Barack Obama
I'll say pretty much what I said in the comments here: I think at a certain point when a course of action becomes a crusade, people lose sight of the likely negative consequences of continuing. I think that’s where the Clintons are now. I think the feeling of heroism Hillary is getting from angry members of her voting blocs is so soul-satisfying that it's become hard for her to care what happens in the future. What's more, I think she respects John McCain enough to only really care about beating him if she gets the satisfaction of doing it. And I think she sees how the Democrats walk on eggshells around Joe Lieberman, so she knows they’re too spineless to punish her no matter what she does.
I think she'll go for something like the "middle option":
…suspend her campaign, acknowledging that Obama has crossed the delegate threshold but keeping her options open until the convention in late August.
But I think she'll refuse to concede that the delegate threshold itself is unambiguous. She'll promise to unite around the nominee (eventually), and she won't attack Obama (although surrogates will continue to do so), but she won't officially stop the fight.
At this point, she’s practically a folk hero in certain precincts. She really might be willing to gamble the rest of her career as a Democrat -- and I think she'd absolutely be willing to risk helping to put her friend John McCain in the White House -- to keep that feeling alive. In some ways, this has probably been the best year of her life.