Probably the biggest and most confusing goings on in creator rights at the moment is the ownership status of Superboy. Here are a few links to online articles about the situation.
In a nutshell, Siegel sued DC back in the 1940s after they lauched a Superboy feature without him. In a decision I don't understand the judge ruled that Superman was work-for-hire and belonged to DC (despite being created years before National bought the first story) while Superboy was not and belonged to Siegel. On possibly questionable legel advice, Siegel sold the rights to Superboy to National for what was probably a low figure, and the creators of Superman were soon thereafter fired, with Siegel not writing the character again for over a decade, and neither of them getting a credit on the books for three decades.
However, thanks to the copyright extensions passed in the 1970s and later, creators and their heirs have some rights to the additional copyright terms, on the logic that the buyer got what they paid for with the law at the time. Therefore, Siegel's heirs were eligible to file to reclaim Superboy, and did so. Exactly what this means has been winding its way through the courts for years now, in particular how it effects the rights to the TV show SMALLVILLE (which has a teenage Kryptonian Clark Kent, living in Smallville with his parents and learning to use his powers, and supporting characters like Lana Lang and Pete Ross who first appeared in Superboy stories, but never actually used the term "Superboy").
Well, that's my understanding of how it stands. As I said, the original decision confuses me, since I think logic dictates that Superman was not work-for-hire, and therefore both Siegel and Shuster (or their families) should have been able to reclaim Superman years ago.
I'm also surprised this hasn't come up more. I think Simon had a filing for Captain America and ended up settling with Marvel, which is why an S&K credit started showing up in Cap comics a few years back, though I don't think too many details of that were released to the public. I've been given to understand that DC has quietly negotiated agreements with some other creators (Paul Norris for Aquaman, as an example) but given their history I have to wonder if they're keeping it quiet in order to lowball their settlements.