Dane,
You're right man, the League isn't as recognizable as say… I dunno, Pirates of the Carribean. Kids of even the toddler age know Pirates is a ride at Disneyland, but do they know who Allan Quatermain is? Unlikely.
As for the media/marketing I can't say that I've been all that impressed with Fox's job on the trailers. But then again, trailers lately have been so-so, just look at T3's aweful trailers and how arguably good T3 ended up being. I'm of the firm opinion that the new TV spots (such as the “Unite” spot) where the characters are named as to who they are represent the flick MUCH better than the trailers.