Looking at a few 5D2 sample videos, I have a few first impressions:

1) the image quality is beautiful, just as you'd expect from a full-frame DSLR. and
2) the skew... well, you can judge the skew for yourself...

Look at the last 10 frames of Canon's long-lens road footage here (I found this from the www.dpreview.com site. It is a 1920x1080, 30p, 275 MB H.264 Quicktime file) MVI_5500.MOV

The camera is nominally locked down for the full take, and heat shimmer disguises any artifacts for the most part. However, at the end, the image shifts slightly sideways in the last ten frames (I presume as someone presses the "off" button.) During that shift, you see just how much skew we are talking about.

There are more sample videos here, one with a rather long (but quite slow) pan. SCS better get their act together and fix the AVC editing in Vegas. This baby shoots 1080 30p video at 40M/s and 15 frames in the GOP. This should be quite editable, but who knows. I guess there is always Cineform.

After looking at the videos here http://web.canon.jp/imaging/eosd/eos5dm2/02.html#01 I have decided that my wife will get me one of these beauties for Christmas this year. Pre-order is in.

Since the resolution of the 5DMkII is so high I wonder if Canon isn't demosaicing the bayer filter but rather doing simple arithmetic averaging, or something similar, to cut down on the enormous CPU overhead required to demosaic 21MP at 30fps and then remap to 1920x1080 and finally compress to H.264. That's quite a bit of work for the electronics in the camera!

By doing something simple like taking each 2x2 filter pattern and making it a pixel by using a weighted average of the 2 green, 1 blue, and 1 red sensor elements they can easily obtain a value for the entire 2x2 element.

Since the raw resolution of the sensor is 5616x3744 the resolution obtained from a simple method like this would be 2808x1872. From here the output could either be cropped to 1920x1080 or remapped to that resolution. Since it appears camera does not work in crop mode when shooting video it appears as though if indeed Canon is doing what I suspect then they are remapping.

It'll be interesting to eventually get the tech details on this as it's pretty amazing they are doing it in a prosumer dSLR.

- Mark