"Canon has announced the Speedlite 600EX-RT flash, its first to include wireless radio control, alongside a selection of EOS accessories. A radio frequency transmitter, the Speedlite ST-E3-RT, has also been released and can trigger up to 15 Speedlites at up to 30 meters. Meanwhile, the GP-E2 GPS unit allows for automatic geotagging of images from the latest Canon DSLRs and the WFT-E7 wireless file transmitter can use either a Wi-Fi or Gigabit Ethernet connection to move files from camera to computer or to control the camera. There's also the BG-E11 dual-slot battery grip for the EOS 5D Mark III.
The radio connectivity is a first for Canon and comes in addition to the infrared triggering found in previous models. Major drawbacks to infrared remote flash control are that it requires a direct line of sight and has a relatively limited transmission range, particularly outdoors. By including built-in radio control, Canon now offers a system that gives its users an alternative to the popular PocketWizard radio transmitters and receivers. The Speedlite ST-E3-RT can trigger up to 15 Speedlites over distances as far as 30m.
The GP-E2 GPS receiver weighs in at under 3oz and offers automatic geo-tagging (via EXIF metadata) of images shot with the EOS-1Dx, 7D (with a firmware update) and the co-announced 5D Mark III. With older EOS cameras the GPS receiver can generate tracklog files at specified time intervals - even with the unit detached from the camera - which users can then manually import into compatible mapping software.
Continuing with the theme of wireless communication, Canon has announced the WFT-E7 wireless file transmitter which can transfer files from the EOS 5D Mark III over a Wi-Fi (802.11a/b/g/n) or Gigabit Ethernet connection. For remote camera setups, the transmitter has a server function that allows for camera control via a web-enabled mobile device. Rounding out support for the EOS 5D Mark III is the BG-E11 battery grip which adds dual battery slots and additional external controls for shooting in portrait orientation."