Jack Kirby, then his estate, have been suing to get royalties from when he worked at Marvel. There was talk that Marvel had capitulated somewhat and was paying some sort of royalty to the Kirby estate for his work, sort of like what DC did for Siegel and Schuster. Turns out, no. DC is still paying a royalty to the Kirby estate, but as far as I can turn up (including talking with industry insiders), Marvel has not paid anything beyond Kirby's page rate. IIRC, Kirby signed a deal in the 80's giving up his claims to the characters to get his remaining artwork back, but I not only don't know what came of that, but also, given how lopsided that is, I question if such a deal is legally enforceable. The Kirby estate has been holding out for simply royalties, but things have been stuck for so long, they escalated. First, they sent notice that they are the proper owners of the characters Kirby created. Marvel retaliated by seeking to have a judge terminate Kirby's claims under "work for hire." Now, Kirby's heirs are stepping up. They are suing Marvel big time. However, here's the interesting wrinkle in their proposed settlement. They aren't after ownership of the characters. Rather, they want co-ownership, and each owner will be able to exploit the properties as they see fit.
Which means, Marvel can still leverage its movie deals and such.
And the Kirby estate can publish and license their own Fantastic Four comics. (Which is just GREAT for me, seeing as how I don't read one FF title, why would I want two?) Mark Waid loved writing Captain America and FF, and as EIC of Boom!, should this work, the Kirby estate could potentially license the characters to other publishers like Boom! Or maybe even sell the property to, oh, off the top of my head, DC.
We're enter a new era, kiddies. Characters possibly going into the public domain while the trademarks are still held, reclaimed ownership, the comic field is about to become a mess.