Isn't the rush on the Siegel/Shuster case because Superman is about to go public domain? Has the (oh so long and drawn out) Siegel/Shuster case changed Supes going public domain?
We have copyright lawyers around here that could answer with more authority, but as I understand it, no.
Superman was created in 1932, and sold to Detective Comics in 1938. At the time, law allowed for copyright protection for a maximum of 56 years. In 1976, the law extended that to 75 years, with a provision that allowed original creators to reclaim rights 56 years after the creation - if they didn't reclaim, the thing didn't go public, it just remained in the hands of whoever held it until the end of the 75 years. In the 1990s, the term was extended to 95 years, with again another provision to extend rights.
So, S&S are the creators - their estates have filed (each separately, at different times) to regain control of the copyrights under these provisions. If, for some obscure legal reason, these guys don't get their rights back, Warner communications will still hold the rights. Superman was created in 1932, and under current law that creation should be protected by copyright until 2027.
It gets more complicated, because all this only applies to the *original* Superman. Stuff added to the Superman character and mythos after 1938 are still owned by DC (which is in turn owned by Time Warner).
