Ok, this is what is really going on today. Hillary's campaign was prepared to concede tonight. She had already begun preparing concession remarks. Then they got word out of South Dakota pointing not just to a Hillary win, but a BIG Hillary win (20+) points *via drudge- who has been spot on in the past few contests with Clinton campaign leaks.
So they took the concession speech off the table. They think they can use the big win (and upset) in South Dakota to be major leveraging power for her. She will insist on the VP spot and point to the fact that he has been mortally wounded as he crosses the finish line. (A wound which she has helped to inflict).
She will go after Obama's supers and point to his poor performance in South Dakota.
She will stop at nothing. Even if he gets the big number of 2118, she will not concede because of the South Dakota win.
And on a personal note, Hillary, you are my least favorite person in the world today. You suck.
Update To those people asking where I get this from, it is from putting together information from a bunch of sources. The SD numbers are coming from Clinton campaign leaks to Drudge. The past few times that the Clinton campaign leaked numbers to Drudge they have been spot on.