Superman has the whole boyscout thing as well as the difference between the bumbling Clark Kent and Superman personas. He's also ALREADY ESTABLISHED in the public's mind. Hal isn't and many people will be asking, "What makes him so unique that we should be invested in a new(to the public) character?". BTW, Thor & Cap this summer have to justify themselves just as much with the same question. Having already seen Thor, I can tell you if there's one thing above anything else they got right...it's making him a unique character(I'm talking personality here when I say character and powers/backdrops don't come into it).