I'm not sure of how it's done on the tech side but 3DTOTAL has the multiple format problem solved. If you go to the site and pick the free models you will see an image of the model with the available formats. On download you are given a multiple view of the item. Then, if you decide to download it, you are directed to a multiple choice page where you select the available format most suitable for your use.
A setup like that would be an ideal solution to one of the problems being suffered on this site.
If anyone in the forums knows how to do this; consider contributing your knowledge to make this a more viable and pleasant to use site.
This has the potential to be a solid growing community site. Keep in mind that, as in any business, a problem solved is money earned.