For a lot longer than I thought it would, this topic has been brought up lately. Most often, I read that the reason DC killed off Conner Kent was because the company can no longer use it, but now I am reading the backside of that as people ask how can there be a Superboy and the Legion of Super-Heroes program this fall if DC no longer owns the rights. Below is my attempt to pull everything together and show that it isn't as cut and dry as some think:
(1) DC has not lost the right to Superboy. The fact that there will be a SUPERBOY and the Legion of Super-Heroes cartoon this fall is proof enough that Time Warner, DC's parent company, feels secure in what owns. I do not deny that it could be saber rattling on DC's part, but it costs too much money to produce a new television show that it would never have gone into production in the first place had anyone in legal thought there was a chance it wouldn't make it on air.
Beyond that, in 52, hasn't Superboy and Krypto just been reinserted into Superman's past? (I ask because I have my copies of the first four issues, but haven't read them yet.) If Time Warner thought it was going to lose Superboy soon, as many have speculated because of Conner's death, I don't think legal would have allowed DC to return the character to prominence in that way.
(2) DC has never really owned the rights to Superboy. Not ever; at best they were leasing the character. The reason is that Siegel, as a freelancer, approached DC on his own with an idea for a Superboy character. How much of the traditional Superboy he pitched then is still up in the air, but because Siegel and Shuster created Superman and brought it to DC (in other words, were Lana Lang, Pete Ross, Krypto etc. Siegel's creations, too, or did he bring just Superboy), any derivatives from the Superman concept they created separately or together were still their property unless they licensed or sold the rights. DC didn't bite at the offer, but in 1945, with Siegel in the Army and Shuster basically blind, DC started running Superboy stories without the permission of either man. In 1947, when Siegel returned from his tour, he and Shuster promptly sued DC for the rights to Superman and, basically, for copyright infringement for DC's use of Superboy. In 1948, the court ruled that DC owned Superman, based on the contract the pair signed many years earlier, but that they owned Superboy. They granted DC the rights to Superboy for $94,000 and DC thought the problem was solved and they owned the character completely.
However, what no one could have predicted, was that in 1976, the Copyright Act would be totally revamped. When that happened, a provision was included that allowed creators of any creative work who had signed their rights away a chance to terminate the agreement when the first term of copyright came up for renewal, provided they gave the licensee notice. This is what the Siegels did. Time Warner, of course, contested the termination notice; IMO, probably not because it thought it was right--there is too much case law supporting the 1948 decision--but because it thought it could outspend the Siegels and force a settlement.
The March 23, 2006, decision did nothing but affirm what everyone already knew: the Siegels own Superboy.
(3) Yet, if the Siegels own Superboy, how can I state that Time Warner still has the rights to Superboy? I say this because Time Warner owns the things that really matter, the trademarks. It owns the S-shield trademark, it owns the Superboy trademark, it owns the Smallville trademark, it should own the Clark Kent trademark, but it has been some time since I last checked the PTO Website and I can't remember. DC owns every single thing that is marketable about the character; what do the Siegels get if they own Superboy, but cannot use the name on the cover of a comic book or license it for a toy? I suggest nothing.
Now, please understand that trademark law is very different from copyright law. Trademark law is consumer protection law in place to prevent someone from using another's more famous, more respected trademark on their shoddy merchandise, which could confuse consumers. Copyright law is in place to protective creative works.
Think about it in this way: Anyone can create a comic book story with a character named "Superboy." Names in and of themselves cannot be copyrighted. However, if in that story the Superboy character copies dialog or drawings from earlier Superboy comic books that DC published, then DC could sue for copyright infringement. Now, if the Superboy character looked and acted nothing like any of the permutations DC has presented over the years, let's say a physically challenged Latino for whom the name "Superboy" was used as an insult, then there could be no copyright infringement, but "Superboy" could not be used on the cover of the comic because Time Warner owns the right to use that trademark on comic books, just as it owns the right to use it on action figure packaging, for instance.
You might see the Siegels' problem in the long run. So, they have ownership of Superboy, what can they do with it? They can't take it to another comic book company since all the elements that make the character Superboy, some of which I listed three paragraphs above, are trademarks owned by Time Warner. They can't use the familiar costume on the comic book cover because that would infringe Time Warner's trademark. They can't use the name on the cover for the same reason. Licensing the character for toys or movies is cut short because none of the familiar elements that identify the character may be used without infringing Time Warner's trademarks.
The Siegels will probably attempt to have Time Warner's ownership of the trademarks revoked or have themselves brought in as co-owners. If they don't, the Siegels may own Superboy in the pages of a non-DC comic book, but if they S-shield and "Superboy" can't be used on the cover, the comic might as well star any generic character with super powers.
When the dust settles, the Siegels should be willing to settle; Time Warner has been willing to settle for a while. I think the case continues, first, because the Siegels want what they deserve this time as opposed to the token pensions Siegel and Shuster were paid starting in 1978. Additionally, there could be some enjoyment on the part of the Siegels watching Time Warner squirm after how Siegel was treated by the people who used to run DC.
However, there is a possible third reason: this could also be a ploy in preparation for an even more important battle to come over the rights to Superman. Legally, Time Warner and the Siegels own Superman equally, and copyright allows equal owners equal use rights, but the Siegels have been pushed out of that market and they want what is legally theirs. Add to that, a nephew of Shuster's who recently came out of the woodwork claiming a share of the rights, and the battle for Superman could be bigger than the Supermen/Superboy knockdown in Infinite Crisis #7.
UPDATE: Since this was written, it appears that Time Warner is taking a step back, at least with the Legion cartoon. Last week, a new press release was issued that referred to "young Superman" rather then Superboy. At first, I thought that it was just a way for the cartoon to grab the coat tails of Superman Returns and the press release coming out the week the movie was released seemed a little too coincidental. However, even before that, at the New York Licensing Show, Time Warner promoted the show to potential partners without any mention of "Superboy," though the S-shield and a male figure in a Superman/boy was featured prominently. A picture of the promotion signage is shown here (scroll to the bottom of the article). Now, there are rumors that the cartoon is going to have any use of "Superboy" dubbed over with "Superman," while the program for the San Diego convention calls the series "Legion of Super-Heroes" and describes it as "a new Superman-themed half-hour adventure series inspired by the DC Comics series." Ask me now, and I would say that Time Warner blinked.