Mubarak just spoke, on Egyptian State TV, to the nation and the world. He did say that he would transfer the powers of the presidency to the vice president whom he recently appointed, although there were no specifics as to what that meant. He also made reference to a number of changes to the changes to the Constitution and to election procedures that he favors, and to the possible (but not immediate) lifting of the emergncy law.
But he also said he would not resign and would not leave and would serve until the election in September. Despite its conciliatory aspects, the speech went over lead-balloon-like with the protesters. It most definitely will not end the crisis nor even reduce the anger against him and will quite likely lead to bigger demonstrations ahead.
(All of the above relies on the English translator on Al-Jazeera, where I watched the speech.)