The Reuters photography blog has posted a story
on the remote-controlled DSLR systems the wire service has been developing and will deploy at the upcoming London Olympics. The post is a little short on details but says "the movement of the camera can be controlled along each axis and the camera operator can control the zoom lens remotely with a joystick." Obviously, it can also be triggered remotely; how the images are transferred off the remote cameras isn't described.
The post includes several interesting pictures of the rigs, including one rafter-mounted unit with a Canon EOS-1D X in place.