I wonder if they (through firmware) will allow for flash control with the 600EX-RT using the 6D's wireless system. I would hope that, at minumum, future bodies would have that master control built in. It's not just the expense of additional components; it is the awkwardness of adding more components to the camera body when often what you need is to just shoot (without more and more weight!)
Makes sense, but...
Quote from: Canon Marketing
It's not just the expense of writing the firmware code to support Wi-Fi flash triggering, it's all that lost revenue from the 600EX-RT and ST-E3-RT units we won't sell if we include the feature. Sure, we did it with the popup flashes on the low end models, but that was old optical triggering tech, not our brand new RF tech.