"We don't to ZIP as a format choice because what really matters for the user is what's in the ZIP (or RAR), but one issue we do have is if you have multiple formats. We might allow people to select multiple (say, up to three). "
It would be cool if we could select the formats on the upload screen with checkboxes, like the categories. Then we could upload a zip and check all the formats it contains. I saw fusebulb posted lots of models in different formats and that makes it hard to browse the new models page.