Disney filed a memo in support of Marvel's claims. They're also trying to block any reckoning as to how much these characters (which include the Incredible Hulk, Thor, Iron Man, the Fantastic Four, and the X-Men) are worth. They've requested that the New York District Court hold off "on ordering an accounting of profits" on the grounds that Kirby's "copyright ownership claim hasn't been validated yet." (Considering Disney bought Marvel for $4 billion, you can probably deduce what those individual characters and franchises are worth.) Disney also believes these copyright claims are invalid because of the statute of limitations. Heat Vision has Disney's memo for those who want to see all the fine points.
Disney's legal department is one that's discussed in whispers of awe and terror. The Kirby Estate has a hard and difficult road ahead of them to try and defeat the Mouse House, who is very keen to protect that $4 billion dollar investment. We'll keep you updated on what transpires, but hopefully a few of you who are legally inclined will weigh in with your thoughts and findings.