Upload & Sell: On
I am a bit disappointed in their vague description of the wireless capability. I see it has confounded some review sites as well. Unfortunately, it would seem that it does not have a dedicated RF transmitter, as I too had thought. Apparently the wireless functionality they refer to is the ability to control all 600exRT functions via the camera LCD. Not a huge advertising point IMHO, since the 600's interface is hugely improved over the 580's.
I've used two 600s in conjunction with my 60D, and triggered them both off-camera, optically, via the 60D's pop up flash. In this sense, I am still a step ahead gear-wise, since using the 5D MkIII would necessitate another piece of gear if I wanted to use both flashes off camera! (Trying to convince myself this is a good enough reason not to indulge in a 5D MkIII !)
For radio-trigger, I've mounted one 600 on my 60D, set it to radio, and fired another in a separate room.