Der Spiegel is pessimistic. An interesting tidbit:
Those who have to remain mobile in London during the Olympics are well-advised to rethink their strategy. The German package delivery service DHL, for example, plans to shut down part of its London delivery fleet, knowing that traffic will be moving even slower in the downtown area than at the typical snail's pace of 11 kilometers per hour (7 miles per hour). Instead, DHL plans to have extremely fit jogging couriers making package deliveries during the games.