The lawsuit could affect all of the various comic franchises in a weird way. According to THR, if the Kirby estate wins the copyright to any characters (and the waters get murky where Stan Lee is co-creator), the Kirby estate could license competing versions to other studios. This seems a distant and crazy possibility, though Disney is reportedly gearing up a huge legal defense to prevent that from happening.
The Kirby estate has also filed a claim under the Lanham Act that specifically targets The Incredible Hulk and X-Men Origins: Wolverine. The estate claims the two films were misrepresented in their promotion because Kirby isn't mentioned as being an author or co-author of the comic characters. The claim is an interesting case of wringing money out of the fine print, because Wolverine isn't a creation of Lee and Kirby, but Blob, Cyclops, and Professor X are. (Somewhere, a Fox executive is kicking themselves for the idea of fun, tie-in cameos!) The Kirby estate is seeking "up to three times the amount of damages they sustained." Hulk made roughly $263 million worldwide, Wolverine made $375, so they could end up with a tidy sum if the judge agrees Kirby didn't receive his fair share and credit. We'll keep you updated on what transpires, and how it may affect your favorite Marvel franchise in the future.