Mattman -- immediate request for a dancing chicken 3D model.
ShockForge -- it would work, but you would have to be firm on the nature of the site, and also try to keep a good, simple, artistic style sheet.
The issues going to be:
Pay... don't do it. Don't let dweebs start posting models and trying to sell them. Maybe some charityware, but no pay. That's weak, and frankly there's TurboSquid for that.
Formats... don't just offer 3DS and X. You'll draw in a broader base of users with additional formats, such VRML, OBJ, LWO, etc.
Poseable models... expect a ton of mechs/zoids type models. They're a gimme if you can manage boning at all. Don't expect a ton of human models.
Low-poly models... if you're going to cater to DB/Developers, make sure the models are realistically suited to their needs. You might want to impose an arbitrary limit (like 3000 polys), and above that require the model under go review. The nice part is, too, down the road you have room to expand the site to include more artsy model types.
Promote a method for reviewing renders of work... Actually, if you want to see a really good example of this (if you can do a good PHP site) try looking at ArtSIG.com. Limited number of members, and everyone either has to critique, or pay for a subscription. Also, this encourages participation and repeat visits.
Submissions... I would keep this under wraps. Let them submit downloads, but don't let it automatically post. For the review section, only allow JPEG renders, no models.
Tutorials and article... Limited to a few folks who are really good.
That, I would say would make a pretty damn good website.
I have a stack of public domain 3DS models on my HD that I have downloaded for various projects. Mostly scenery items like chairs, tables, a few trees and plants. You can have all those files!
I think if it becomes aparrent to folks that they gain access to a lot of good models, you'll see submissions, since that will be a good trade-off.
It wouldn't hurt to impose a submission-for-downloads system. Where say one submission entitles you to ten downloads.
Plus, you'd need a freebies section, where the lower-end stuff could be had without any trade.
We can't stop here! This is bat country!
