The La Times breaks the story:

U.S. envoy tells Egyptian President Hosni Mubarak to step asideFrank Wisner, an envoy sent to Cairo at President Obama’s request, tells Hosni Mubarak that he should not be part of the ‘transition’ that the U.S. has called for. ‘This message was plainly rebuffed,’ says a source…
WASHINGTON — A U.S. envoy in Cairo told Egyptian President Hosni Mubarak that he needed to step aside and allow a new government to take shape without him but was rebuffed, according to Middle East experts who have discussed the matter with the Obama administration.
Frank Wisner, a former ambassador to Egypt who has good relations with the Mubarak regime, traveled to Cairo at President Obama’s behest to talk to the Egyptian leader about the country’s future.Wisner delivered a direct message that Mubarak should not be part of the “transition” that the U.S. had called for, according to Middle East experts who spoke on condition of anonymity.
One expert on the region said that in his regular conversations with the Obama administration about the unrest in Egypt, he learned that Wisner’s message to Mubarak was that “he was not going to be president in the future. And this message was plainly rebuffed.”It wasn’t clear whether Wisner specified a timetable for the 82-year-old leader’s departure. It also wasn’t clear whether Wisner contacted Mubarak in person or by telephone. The experts described the contact on condition of anonymity. White House officials declined comment on Wisner’s mission.
In another sign that the Obama administration is planning for a post-Mubarak era, the U.S. ambassador to Egypt, Margaret Scobey, has spoken to Egyptian opposition leader Mohamed ElBaradei, a Nobel Peace Prize winner who has called upon Mubarak to step down.The contact with ElBaradei was confirmed in a tweet by State Department spokesman P.J. Crowley as well as by a senior administration official.Since the crisis unfolded, the White House has been careful not to publicly take sides in the dispute. The Obama administration is calling for an orderly transition in Egypt but has avoided taking a stance on Mubarak’s fate. Rather, U.S. officials have said they do not want to be seen as picking Egypt’s leaders and that the nation’s future should be determined by its own people.
But the Wisner visit is the latest in a series of indications that the White House has drawn the conclusion that Mubarak cannot realistically remain in place. President Obama will be briefed by his senior national security team on events in Egypt at 3:30 p.m. EST Tuesday.