You make excellent points. 5e IS a great development. I was in on the open beta, myself. And I would like to say for the record that I'm a huge fan of setting materials, plots, adventures, and other things I can easily adapt into my campaigns. I would encourage everyone who is interested in doing so to have at it. Note that I would hope for system agnostic material, specifically, so that it could be applied equally to any and all versions of Dark Sun in any system.
However, respectfully Flip, you also strengthen my point.
It is not your job specifically, but it IS the job of Athas.org to produce 3.x content. Nothing more, nothing less. I do believe that the license for Athas.org was contingent upon continuing to produce 3rd ed specific material, in fact, as it was for all of the officially designated sites. Failure of the site to do so, may be failure to perform the job specified and agreed to, and may also be potentially a violation of said license. I don't want that.
Now, having said that, I don't believe that "Athas.org's job of 3.x content" automatically translates to it being YOUR job, Flip, or raddu, nor anyone else's specifically. After all, doing a job one doesn't like and aren't vested in means crap for quality. Flip prefers FATE system these days, and also prefers to work on Dark Sun setting materials, in Flip's own words. I want you to work on what you want to do.
I also want Athas.org to continue to produce content, rules, settings or otherwise for 3rd edition specifically, as is mandated. I would like to see that those who ARE interested in tinkering with the rules for 3rd edition in manner compatible with Dark Sun be allowed to do so, openly, officially, and formally - with the resulting material posted as "official content" on this site. Also in fairness, I note that producing system agnostic setting materials, which would by definition be compatible with 3rd edition among other systems, would sneakily and technically fulfill the license mandate all by itself. (which may be shooting myself in the foot, but oh well.)
In summary, those who want to work on setting material should be allowed and encouraged to do so in an official capacity. I suggest that setting material be system agnostic, so as to allow for adaption to any and all systems, D&D related or otherwise. Those who want to use this site's official status as a vehicle for tinkering with 3rd ed rules in a manner compatible with Dark Sun, and/or otherwise continuing to produce 3rd edition specific Dark Sun material of all kinds, should also be allowed to do so in an equally official capacity.
So there are my hopes and desires. And here is a bit more of my thinking: If I were to work for WotC, I would have to work on what I was assigned to, not necessarily what I wanted to. If I produce my own stuff, using the OGL and d20 system, I would be third party material (not to mention being unable to use or reference non-OGL material).
However, here at Athas.org, there is a unique opportunity to produce material, in my favorite (if clunky and seriously in need of some editing) system and, as a whacked out bonus, anything accepted would even count as official content. (Not to mention that I'm a huge psionics fan - I pretty much only play psionic stuff these days.) So, yeah, that all motivates me too.
If I could buy the license for all of 3rd ed (or the whole of d20 for that matter), I would, so long as I could work in "being counted as official material per WotC" into the agreement. And that is also part of why I harp on this whole "license and mandate for 3rd edition" stuff so much (I'm sure some are getting tired of me repeating it). I mean, if you had a chance to be an official contributor to the company who produced your favorite system, wouldn't most people jump for that? (I guess that's basically what I'm trying to accomplish, in part, here.)
Is there anyone among the templars, councilors, and/or other leadership of Athas.org who would be willing to spearhead such an initiative, or perhaps simply serve as a point of contact and guidance for someone else who is interested in doing so in an official capacity?
(Oh, by the way and as an unrelated side note, I'm on my 3rd or 4th (?, anyway definitely the final) pass of the material for that project I'm working on, about 1/3 of the way through. Once I finish this pass, I'll be delivering it.)