In video 34_DNG there is mentioned that we now have more than 280 different propitiatory raw file formats, because Adobe have to reverse engineer the file format for every new camera. I can understand that, but that doesn't mean that the file format as such always is different, just that Adobe don't know the whole truth of the file format.
Just for fun i put the CF-card from my new Canon 5D MkIII into an old Canon M80 hard drive with a display (used to back up images in the filed in the old days), and it happily showed all the images. The colors even looked OK. So when a 6 year old device can render CR2 raw-files from a new camera, I suspect that CR2 might be some sort of propitiatory format that is common among all Canon cameras that use the CR2, not one format pr. camera.
What is really going on here? I can see that a new profile is needed for a new camera in LR, but that is not the same as a different file-format. Why can old Canon cameras and devices display raw-files from new cameras made many years afterwards?