Alongside the D7100, Nikon announced the WR-1 Transceiver, a unique radio-frequency wireless remote control. Able to remotely control multiple cameras capturing stills and videos, and even time-lapse sequences, the Nikon WR-1 Transceiver mounts on the camera’s hot shoe, but communicates via a cable attached to the master camera. Expected to retail for £649.99 in the UK, the WR-1 will ship in March 2013 (US pricing has yet to be announced).
News: Digital Photography Review (dpreview.com)