Unfortunately, I think the Cinema EOS 4k concept camera will be a $20,000 product- it was announced to keep Canon video users from investing in Scarlet-X, the only other 4k capable camera out there within reach. If the HD-only C300 is $16,000, it seems unlikely they would undercut that with a 4k DSLR at a lower cost. Of course, I hope I'm wrong.
My hunch is they'll improve the video in the 5DIII to match the 1DX (with maybe a few other goodies- HDR video, anyone?), and let us, the low-budget filmmaking crowd use that while they market the 4k Cinema EOS camera for the Hollywood/rental market/higher budget crowd.
There is nothing suggesting the CDSLR will cost that much, just bc it's 4k doesn't automatically mean it's going to be more expensive (Scarlet is 4k and costs less than the C300. I'm just saying that if the C300 was their "big gun" they would have waited and announced that first. It would have been foolish to release a new camera and announce a better camera at the same time.
I doubt it will have HD-SDI outs, built in ND's, etc like the C300. If you figure the 1DX is $6800, take away the costs for the crazy AF and the 10-12fps and I'm sure it could be taken down to $5k. What could they possibly add to that body that would increase the price by $12k-$15k and make it a better camera than the C300?
Technology is getting cheaper by the day, and hell the new iPhone does 1080p and looks damn good for what it is. This camera isn't going to be announced for another year, so who knows how much cheaper things will be by then.
Even at first glance it seems apparent that the C300 is the superior camera (based on looks of course). If the CDSLR is $20k that would mean that the 5DIII is the next video DSLR (even though both the previous 5D's were still cameras), and that move just doesn't make sense. There are photographers that never use the video features on their 5DII and there are videographers that don't use the still features of the camera, so why make both segments pay for features they don't need/want?
I could be completely wrong about all of this, but that's my reasoning more or less.
Last thing, check out the group shot of all the cinema gear :
If the CDSLR is the "flagship" of the line why is it tucked off in the corner?