And the cry goes out far across the land: Siegel heirs get copyright on Superman from Action Comics #1. Warren Ellis, Colleen Doran, Mark Evanier, Newsarama, and the New York Times have all proclaimed the news. Frankly, I'm not sure what it means for the Siegels, and who gets what and what it all means is to be determined. Also, copyright law make Zathras' head hurt. But it has to do with the US changing copyright from (I think) 29 years and renew for same to one period of time that is a couple of years shorter than the two previous ones. To rectify that gap, they offer the opportunity for any claims to copyright to be filed to keep certain copyrights from falling between the cracks, or unjustly held. The Siegel heirs filed within that time. Unfortunately, Joe Shuster passed away before that and he had no direct heirs who could file, which is why only the Siegels are the ones involved. I do not know, I don't want to add to the noise, just think of this of us talking in the breakroom and I'm trying to answer your questions the best I can, so if you read something anywhere else both within and outside of these internet tubes, I would defer to what they said. Mr. Evanier recommends reading the first link I used to get an understanding of what's going on, and I'd recommend the New York Times article.