It's actually somewhat unclear. They say that they support ".raw" files, but that suffix is only used for raw files from Kyocera Contax and Panasonic cameras. They specifically don't list .NEF (Nikon), .CR2 / .CRW (Canon), or .DNG (the "standardized" raw file format).

http://www.amazon.com/gp/help/customer/display.html?nodeId=2...