Mubarak isn’t stepping down. Whether that’s the right or wrong move, I honestly don’t know. But the crowd in Tahrir Square is already exhibiting the characteristics of an angry mob. They’ve gone from full of hope to anger in mere minutes. (This is an almost unimaginably huge mob.)
UPDATE: Richard Engle just reported that protestors have begun a march to the Presidential Palace. He does add, however, that they may be directing their main efforts and energy toward an even larger march tomorrow.