I think the new system is a step in the right direction and I can't wait for the radio trigger to be integrated into a camera body. Perhaps the 7D2 will get that - just like it was the first to get the built in ST-E2
I wonder if the controller isn't integrated into the body because of the potential for RF interference. It was long enough that I don't remember if it was the 5D or 5DII that was experiencing banding problems with certain lenses and it turned out to be because certain lenses were creating some type of RF interference. At least that is my recollection.
As far as the OP's question goes, I've been waiting for this flash system since the first patent was announced—really before that even. I think it is the bigger deal. Having said that, I am more excited about the 5DIII. Yes, it doesn't have the killer "first-to-affordable-full-frame" of the original 5D or the "21 megapixels?!?!" &
"look at that video!" of the 5DII. But the 5DIII is finally a complete camera. No crippled anything. It is exactly what I've been waiting for since the EOS 3. And if it really offers improved low light IQ, then wow. Everything on my want list has finally been crossed off...well, everything except integrated RF control of Speedlites. And, now that I think about it, it would be nice to be able to configure it on the computer. And how come I still can't focus during video shots? Hmmm. I see a 5D4 in my future...