The prototype look different from the final product for all the recent releases. .___.
Hmmm, not really. If your talking more recent releases say for example W's release, there's not much of a difference when you compare the 'prototype'(the one we saw in a hobby magazine?) and official release photos.
Personally, the only the things that were slightly different(by slightly, I mean very subtle) were the obvious un-compounded eyes and mouth. The mouth change was the most noticable, since the prototype was more jagged and stuck-out alot too. The final version was more smooth, for lack of a better word.
Once I take a closer look at OOO's SIC, it does have compound eyes leading me to believe that it is the final version.
Then again I could be wrong, as there is no clear release date yet. So anything goes (pardon the pun, hehe), I guess. But so far I'm happy, but if there are improvements to be made, the designers clearly have the time.