Maybe uncompressed, but with a very short time limit and delayed saving? An 8GB buffer or the like would be pretty feasible wouldnt it?
Otara
Unlikely, it'd be pretty expensive.
Well, as long as those specs aren't public, we can keep dreaming! ;-)
About 10 years ago we were talking about the new digital cameras and how none ever thought we would have a 24MP camera... In time it's astounding how many dreams do come true! ;-)
Actually once the 1Ds came out, the discussion was about resolution doubling every 3-5 years. Remember we were supposed to be in the 30+ range now. We're falling behind! 
My comment was about transferring clean 1080P to a secondary device. SSD? Recorder etc. Its clumsy for underwater but my comment was more general.
The other part of the argument (or dream) is more related to autofocus filming. Might we have an improvement here. I might not be up to speed on Canons camera offerings, but they didn't have this feature last I looked. (and yes we can also discuss how useless/full this is at present).
Sure, they could do that. But with no full manual control, it'd be useless. 3 gens down and they still haven't put that in?
As for AF in video is something I think that Canon won't put into their cameras because it's unreliable. I certainly don't use it and neither do most people using these cameras in video mode. Especially with the breathing in lenses, it gets pretty ugly. Mirror flip AF using the phase array seems the best of both worlds, but it leaves out the people who can't focus pull 
Regarding XQD heat issues, do you know something we should know? The claim thus far is for 125MB/s and up write speeds.
The heat comes from processing and compression. Same for any other recording device. That's why all the cameras overheat at some point. And the heat can affect the image output with sensor noise. Like the fictitious D4, XQD may promise super speed but CF in UDMA 7 can't sustain at max speed and video is about sustained data rates. Plus it'll only be announced in Feb.
Jeff, uncompressed means there's no compression except for the processing to feed out the 16x9 image, along with whitebalance, color settings etc are already set. It's not uncompressed RAW as in what something like the Ikonoskop outputs. Red and Arri are compressed somewhat.