This should be fine with the anti-piracy stance of the forum as they were extracted from a legit copy, but yeah here’s all the artwork from SF4’s gallery, sans one stage image that got missed (It’s been sent to him and should be up soon).
A friend of mine translated some of the stuff, though not much of it is development related. However there is one interesting bit: in the character concept art you’ll notice images for a black character that went through several redesigns. Apparently this fellow was “King Cobra”, and was meant to be a more acrobatic counterpart to Ryu and Ken, and possibly bald. He kinda made it into the game to boot, but not in a way some people will like.
Anyway, didn’t see it posted, so enjoy.