Could we downsample the RAW to 8 - bit? Would that be too much for the CPU to handle in real time? It wouldn't be as glitzy as 10 / 12 bit... But most of us that have prior experience with canon cameras (I've been shooting DSLR since 2009 on the t2i) know that the sensor in this camera is only capable of so much. If I remember correctly the c100 shoots 8-bit hd video in avchd 4:2:0, so in theory it doesn't sound so bad. This is baring in mind the special 8.1 MP sensor on the c100.
In theory this would set raw at 8 - bit per pixel (I believe), it seems to me that would be much more likely to support (near or at) HD/2k sizes in a raw continous stream. My math figures it would be below 40 MB/s which would allow a cieling so that Global Draw can be enabled during recording. As a bonus this might offer some really high frame rates to 5D mark III RAW, and maybe open the feature up to older cameras.
I know we don't even have proof of concept for the 12 / 10 bit yet, and I know the 650d still burns strange AF artifacts into the images. So those will definitely be the first and most time consuming. But, can someone tell me if this is an option?
Maths:
1924 pixels by 820 pixels = 1577680 pixels per raw image
Which would work out to 8 - bits or 1 byte per pixel resulting in 1.5046 MB per frame or
36.2 MB/s for what could be 24 fps scaled at 1920 x 820 2.34 : 1