Four of Jack "King" Kirby's children have filed 45 "notices of termination" to Disney, Marvel Comics, Sony Pictures, Paramount Pictures, Universal Pictures and 20th Century Fox to regain copyright ownership of a number of characters created by their father, including Thor, the Fantastic Four, the Hulk, the X-Men and many others.
Kirby's children are filing under copyright law, which states that creators can seek to regain copyrights 56 years after first publication and can file their intent to up to 10 years prior. Kirby's children are eligible to claim their father's portion of copyrights to the Fantastic Four in 2017, to the Hulk in 2018, to the X-Men in 2019, among others. These copyrights would then last for an additional 39 years.
Marvel has declined to comment, but a spokesman for Disney said:
"The notices involved are an attempt to terminate rights seven to ten years from now and involve claims that are fully considered in the acquisition [of Marvel].".
This seems like normal procedure and their no indication that this lawsuit will affect any of the Marvel character movies currently in development.