It appears that videographers are mostly underwhelmed by the 5DIII video enhancements.
If Sony play their cards well, the A99 might become the DSLR of choice for videographers.
There were a lot of people that thought that about the A77, that it would replace the 7D because it did sports well (high frame rate, 1080/60, video AF). Except, in reality it sucked, their lens selection is bad, and the delay to market made the 1DX delay look short. I was pumped for the A77; I got a 60D instead and never looked back. And when the reviews came, they were the same as the other Sony cameras. "If they worked, they'd be amazing, but they don't".
So, an underwhelming camera, given a full-frame sensor and nothing else, still is probably an underwhelming camera. Even if it's the same Sony sensor as the D800. And full-frame will just make their lens selection look worse. You're basically limited to Zeiss price levels for anything good. With Canon and Nikon, you can at least find some value in their primes