The problem with the Clinton campaign is that she is running against someone who is almost universally likable, and the Obama campaign has been nothing less than flawless. If you look at their stances on the issues, they are almost identical in every way, so the only thing Clinton has to campaign on is her experience in the White House and as a New York State Senator (a job at which she has performed very well) and on character. This leaves Senator Clinton in a tenuous spot because of that past experience in the White House has left her as much of a maligned figure as she is a loved one. Senaor Obama on the other hand, has no negative past to speak of, and is seen (rightfully so) as the more positive candidate.
Senator Clinton I believe will continue her campaign, and I think she should, they are virtually even in the number of delegates they have, and as long as that is close, I don't see any reason why she shouldn't continue to press her case to the public. But if the time comes when she start losing primaries bigtime, I believe Clinton will bow out graciously, and make an outstanding Vice-President too!
"Who is splendid among men, who is glorious among heroes?"
--excerpt from Gilgamesh