As I recall, on Super Tuesday the early exits were very grim for Hillary, but on television the word from Clintonland was that she was going to wind up having a strong night. I'm not getting that sense tonight. Andrea Mitchell's first dispatch from Clinton headquarters seemed to reflect a fairly dire mood, and there was a good bit of talk about scenarios in which she would drop out. Tim Russert averred that, given a narrow PA win, it might make sense for her to exit on a high note after a "victory." (I think it would be pretty weird to drop out after a win, but I guess it's been a weird campaign.)
Update: I don't know what numbers the Clintonites were assuming when they talked to the NYT's Pat Healy but in this story freshly online they don't sound on the brink of surrender:
As Pennsylvania voters cast their ballots in Tuesday's Democratic primary, Senator Hillary Rodham Clinton and her advisers were already preparing for an all-out battle through the last nomination contests in early June, though many in her camp agree that she needs victories, not only in Pennsylvania, but also in Indiana in two weeks.
Clinton advisers were predicting a victory over Senator Barack Obama in Pennsylvania, though a narrow one. Indeed, two associates of Clinton said she was taking nothing for granted, and they even predicted that she would end her campaign if she were to lose this primary.
Trailing Obama overall in both the popular vote and in the competition for delegates, Clinton's advisers said they were girding for a tough spring. The Indiana and North Carolina primaries are next up, in two weeks, and Clinton advisers said that if Clinton were to lose Indiana — a state where she has campaigned steadily and has some endorsement advantages — several advisers would urge her to quit the race.