Hosni Mubarak has stepped down as president of Egypt a little over a half hour ago, handing power to the military. He is currently thought to be in Sharm el-Sheikh, in the south; no word on whether he'll be staying there or hopping the border.
Any questions about what happens next seem unimportant to the crowd in Cairo. They'll figure all those questions out later. Right now, they're just rejoicing in the fact that Mubarak is out.