First of all. I am, all of a sudden, utterly unimpressed.
Sample images, at the very least, should make sense. Looking at the shutterspeeds and aptertures used in some of the shots makes me wonder if the photographer had shot those scenes for the first time. Take the football picture for example. He shot it at 1/8000s at F4 (on a new 400 2.8 IS II none the less). Looks to me like it was shot in bright daylight. Not nearly what you would expect for a stadium environment. Of course there are daylight matches, but most of the soccer would be shot with flood lights, mostly in the region of 1/1000s f2.8 and iso 1250-2500. Also the detail level (not only in this shot) doesn't impress me one bit. I have much clearer pictures with my late 2007 1Ds3.
Also, a camera with a standard ISO-range of 100-51200, one would expect to see some low light indoor-sports or concert photography samples.
Canon, you better redo those sample images (let them make sense please) or people will assume that this is the image quality they can expect of the new 1Dx and might consider going for a 5D series camera after all.
When I saw samples (with the preproduction model) and talked a bit with Canon Ambassador Frits van Eldik
http://cpn.canon-europe.com/content/ambassadors/frits_van_eldik.do at a seminar, I got a different feeling about the 1Dx. Those samples do not represent what I've seen and heard there.
just my 2c
