Well this topic has certainly grown.
Indigo: I'm surprised how in depth you went with your answer, very glad you could explain your choices. There are points you mentioned about the leg that I don't find correct considering pose, angle and forshortening, but I don't think it's necessary to bring it up. I actually didn't think that the shoulders could be bending back when I was writing. Now that you've mentioned it, the pose would make more sense.
Instead of discussing the pose and anatomy, I think I'll rather bring up the shading as it's been mentioned a lot. In my first post I pointed out that the shadows on SFIII sprites are usually blue in tone, taking into the account what the others have mentioned, I tried a little edit to make it fit with the style:

(It just accrued to me that the little edit has taken all day...)
I've here taken away most of the volume to create that somewhat cell-shaded look. The original sprites have little or no highlights on the skin. I've toned the greens to make them more yellow and then shaded blue shades in the shadows. There are sometimes dark lines separating the blue and yellow areas as seen in the Alex sprite (the guy in green pants), but it varies where they appear, so I didn't use it much. The hair for the characters are mostly very basic, but it can look a bit strange at times, so I just toned down the details on the top. While I was doing this, I noticed that the forarm somewhat lacks muscles compared to the bulgy upper arms. Don't know, just hit me. Once I shifted the colours, I've noticed that he looks a lot like Blanka from SFII in terms of colours and design *shrug*
I would say that your sprite compared to the SFIII ones is a lot more complex figurewise. I really love the SFIII shading, so I guess I'm kind of biased in that sense, but you've got a great feeling of volume here. Would be a shame to drop it.