If you take a look at the screenshot of the Draugr Hero on the official skyrim media section, you'll notice that he is quite muscular. Another thing you should note is the only race it could be is a nord. The dragonborn hero from the trailer is also seemingly a nord, but not quite as buff.
Is there possible a physique progression with increased STR? Not unbelieveable. If that be the case, then its only fair that every stat influences your body's appearance. This is interesting from a modding standpoint, because there must be some kind of system to simplify all these .nif skeletons to avoid clipping. This coupled with some bleeding edge havok behavior animation software is going to make mods that were once impossible pretty simple compared to oblivion even with OBSE.
Ok Bethesda, I hope you guys made some pretty powerful high order programming software with minimal low order scripting.
....ok enough drooling over the creation kit,...
What you guys say about the screenshot nord vs. trailer nord? Difference in muscle mass? Yay or Nay