What about being published in a fanzine like Freelance Traveller or Imperiallines? I don't see Mongoose publishing a random planet map unless it is part of an adventure. But I could see a periodical having a feature where they spotlight a world and provide all kinds of deep details, including a map.
But my question was more along of the lines of what is needed to make a map good enough to publish? What level of details? Do you need more than just a map, but history and background? Those types of things.
Imperiallines isn't a fanzine.
Mongoose has had a standing request for short works for some time.
Freelance Traveller is a good way to get noticed and maybe recruited for future work. "There's this guy in FT who always does world maps..." A good website can do the same thing, and those are in shrinking supply.
"Good enough" remains an elusive target that changes with context. Remember that many worlds have only as many people as the average saturday afternoon shopping mall living on the entire planet. How much of a world is needed when all of the population lives and works within one world hex? Well, expect Crazy Eneri, and he's just in the next hex over.
There is a concept in T5 that is summarized by the acronym MOARN. While it is intended to make the life of a Referee easier, it also applies somewhat to projects like this: "Map Only As Really Necessary". As an example, I suspect Don and Marc wish the T5SS project had not been necessary. Reams of randomly generated UWPs for the entire Imperium that sounded like a good idea in the early 80s have proven to be "more stuff to double check" thirty years later. Mass-produced world maps would fall into that category as well.
There is also the risk of stepping on toes. As the posts above by Hans (and most of the GURPS book on the Marches, for that matter) show, one person's labors of love can inadvertently pave over another person's long time campaign. Whole editions of this game get ignored by people who had one point of disagreement with a published book, so official print is not immune to the problem.
All that said, I'd suggest embarking on any large-scale project with eyes open. If I were doing this, I would avoid the Marches unless I was actually running a campaign on those worlds. Were I doing this in some other sector, I would still limit my work to worlds I was campaigning on so that every map had context, history at my game table, and a reason to be used. The differences between this sort of creation and quadrants full of random are legion, but they make a difference to (many) end users as well.
