I'd just note that Ozzy uploads all of his mods here for free.
Whilst I'm keen to agree that anyone should be able to upload to the directory, there would have to be some kind of verification process (just to ensure quality of addons) and they should be free only imo.
So as of right now, if you would like to publish your XenForo add-on then please send me a PM and update your Account Details with your XenForo Validation token. As of right now however we will only be accepting "Free" add-ons until we have fully developed rules and guidelines for paid resources. Once that is done, we will open the floor to paid add-ons.