Did we know? Boy, howdy! It was a big deal among die-hard Red Sox fans, because not only did FOX interview Jimmy Fallon during the World Series (he's a Yankees fan anyway), he and Drew Barrymore were allowed out onto the field after the win (whereas, actual fans were held in the stands behind 3rd base).
They filmed for a while in Boston mid-season, you know, stuff at Fenway before and after games. I think several players got on the "acting" bandwagon as well, and will show up in the promo stuff. (Bleah!)
Apparently, they'd intended the movie to end "bittersweet", with the Sox losing, but whoops. They had to rewrite and reshoot a lot in November.