It's my understanding that super16 doesn't do anything anamorphically to the negative when filming, it just crops the image to a rough approximation of 16:9 at the gate. If your intentions were to originate on film and deliver the final product digitally, couldn't you just film in standard 16mm, get a high def transfer of that 4:3 footage, and crop it to 16:9 in final cut pro? It seems like that may even be a better way to go, considering you have more lee-way in reframing any of the shots, since you have top and bottom of the image in each frame.
What do you all think?
-Chris