Norton dropped from Hulk credits

It's interesting to think that the Writers Guild of America, who ultimately decide the writing credits on all films, have announced that Zak Penn will receive the sole credit for The Incredible Hulk and Edward Norton will receive nothing, and while you ponder on the possible injustice to Norton you have to wonder why they did that. I'm not up on the workings of the WGA and how they decide on ... [link]