According to Politico's Mike Allen, a "surge" of super delegate endorsements for Obama are expected throughout the day, likely enough to secure the nomination for the Senator from Illinois.

From the Politico story:

A tsunami of superdelegates is poised to rush to Sen. Barack Obama (D-Ill.) over the next 12 hours, giving him a mathematical lock on his party's presidential nomination.

The superdelegate surge is likely to swamp a few holdouts within the camp of Sen. Hillary Rodham Clinton (D-Ill.) who have been resisting a prompt concession.

The endorsements are expected to continue until after the last polls close in Montana.

Shortly after polls close in Montana at 10 p.m. Eastern time, as many as 28 other superdelegates -- including House members, senators and governors -- could quickly follow, according to statements they have made to Politico and other news organizations.

Obama aides are hoping that he'll be able to announce victory when he speaks in St. Paul tonight, but they say they aren't positive he'll reach that level in time. But the nomination should be his within hours after that.