I agree Headwax, and here's why:
1) As you say, the Anim8or community has been getting steadily quieter, possibly as a result of there being no upgrades to Anim8or for a couple of years now. If opening up the rules would encourage more input and greater activity then that can only be of benefit to the community as a whole;
2) Since it is perhaps reasonable to assume that there will be no more upgrades to Anim8or, perhaps it is also reasonable to think of Anim8or as less a fully-functioning, concept-to-finished-product package, and more a step in the process, as Headwax suggests (I do hope I am wrong about this btw, it would be a pity if Anim8or were never to reach V1);
3) Any rules on what is, and what is not allowable in challenges etc should be consistent and logical. Anim8or's built-in UV control is a bit simplistic, as a result it has always been allowable to use external, 3rd party UV mapping software when texturing objects, so why should it be any different with the renderer or any other function?
My personal opinion is that challenges could perhaps come in two types:
1) Open - Any software can be used in the production of the image/animation, so long as Anim8or is one of them. Further, all software used, and what part they played, should be declared on submission of the piece. This will serve to 'spread the word' to the community about what other software is out there which can help them with their chosen form of artistic expression, and after all, that's what it is all about, yes? It will also serve to spread the Anim8or word to the greater 3D community, since submissions could also be shown in forums specific to the other software used in the production, with the comment "Modelled in Anim8or" in the credits, for example.
2) Restricted - Only Anim8or can be used to generate the final image/animation. Whether or not any other software can be used in pre- or post-production, such as texture processing, UV mapping, rendered image layer compositing etc. is open to debate. Perhaps these could be banned in some challenges, where the challenge is specifically designed to showcase or develop a particular technique or function (eg. edgelooping).
Anyway, it is food for thought. At very least I would put forth the suggestion of setting an 'Open' category challenge as an experiment, to see how it pans out. I would also suggest that more time is needed, as unfinished entries tend to outnumber actual submissions, and what has worked quite well in challenges on Animanon was a monthly cycle. This is particularly true for animation challenges, but also applies to challenges where a 'beauty image' is required rather than a demonstration of understanding a particular technique. Anyhoo, it's food for thought, and thanks to the Anim8or admin team for continuing to keep the site active and providing a place for suggestions like these to be aired.