The new mayor of Moscow is Sergei Sobyanin. He replaces the long-standing mayor, Yury Luzhkov, who was dismissed by President Medvedev in September.
Mayor Sobyanin is being portrayed by the Russian news agency as a Putin loyalist. He was the former head of the presidential administration under Putin. He was also the former deputy prime minister of Russia.
He has no personal connections with Moscow. He was previously mayor of a small Russian city. So, he has been parachuted into the position by the incumbent regime.
Interestingly, one of his first decisions was to allow an opposition rally to be held in Moscow this Sunday. There is an article on the decision here.