Theatres may not prohibit kids under 13 from viewing, but many parents will....PG-13 isn't like R. Theatres don't prohibit children under the age of 13 from seeing the movie, and they don't have to be accompanied by an adult or guardian. Lucas will still make his half-billion dollars.
I actually thought Lucas would really try to "bridge the gap" with this film. Meaning, he would go out of his way to pander to the young audience. Why not make it PG? It's not like it would actually PREVENT the dude in his late 30's-early 40's dressing up like Bobba Fett and camping out for his tickets one opening night/week.Actually, I think PG-13 is a smart move. The last three SW movies (including Return of the Jedi) pandered too heavily to children and suffered because of it. The original Star Wars and The Empire Strikes Back were darker and edgier (prior to the "Special Edition" re-releases), and far superior films.