But wait, what the hell does that mean?
This is what I refer to. The host admin determines who has control of the mod's official info page, official download location, official forum; basically, everything that makes someone's contributions to a mod official. If someone else gets control of all that, then their work now appears to replace any versions that came before. That is the sort of thing we need to be careful about, and strive to obtain permission if at all possible before passing the status of "official" handler of a mod to someone else (or taking up the reigns ourselves).@Sim DingO:
If you are suggesting that the host admin would act as a custodian to protect the integrity and quality of your work in your absence (for whatever reason), I would say that sounds like a good idea, and would be in favor of that myself. If nothing else, the natural reluctance of the individual to *be* a guardian would ensure that nothing unpleasant happened to it.
However, if someone wants to make and release a patch to Gavin to randomly make him part barbarian and remove his ability to rationally discern appropriate romantic partners, that's perfectly acceptable. Assuming all host admins can stay on the ball and consistently practice basic common sense, this person will have to host and support (creating a forum, etc.) their patch themselves, and thus the original author can be secure in the knowledge that no one will be subjected to such travesty unless they deliberately choose to be. However, this all holds true even in the case of rogue patches/upgrades that are actually good - the author (or current author) always has say over what goes in/becomes the official version, even if the decision is arguably to the detriment of the mod.
An author does not have say over whether people can distribute changes or derivative content clearly labeled as unofficial, however. Oh, the law may (may) allow them such ridiculous control, but few are obsessive enough to actually pursue legal action over something so trivial. More importantly, the law only determines legal and illegal, not right and wrong, and as far as I'm concerned it's perfectly moral to enthusiastically ignore an author's wishes on this matter. Because I think wishing that nobody make derivative content of your work is not only unrealistic but selfish; an immoral wish that should be violated.
The rights I believe an author does have: The right to receive credit for their work, the exclusive right to profit from their work unless they grant permission to someone else (for purely practical reasons, and only with completely original work - so obviously this doesn't apply to mods), the right to restrict distribution of their work (otherwise the profit bit becomes hard), the right to be notified of derivative work if it is reasonably easy to do so (obviously it's not easy to notify George Lucas of your Star Wars fanfiction, but notifying jcompton that your NPC mod includes banters with Kelsey is), the right to have their opinion heard about any particular derivative work (if jcompton hates the banters you wrote for Kelsey tell people this up-front before they download anything), and the right to be treated with courtesy and respect just by virtue of being human (which means among other things that you would make a real effort to listen to jcompton's concerns and if they are legitimate, change/remove the controversial Kelsey content accordingly). Adapting my parenthetical examples to other types of "rogue" mod content should be easy enough.
Now, though I basically think anyone is allowed to modify anything in any way they want and make it available for anyone else to download, there should still be some restriction, for the sake of tidiness if nothing else. Mostly just one restriction, though, actually. Don't distribute a repackaged version of a mod with your content added to it unless you are the "official" developer of that mod making a new official version of it. Otherwise, post a link to the official version, and then provide your own content as a patch to it or a separate installation (prominently dated alongside the version number of the official mod it was made to modify). I figure that makes it clearer to lay users exactly what it is they're downloading, and as I said just keeps things much tidier for the community as a whole.