Be able to sort documents by whether they've been fully translated or not.

Add an option to push articles to people based on their interests.

Add an option to push articles to people based on the words that need practice.

Allow people to create documents of their own driven from the lessons that they've completed

At the end of each lesson, suggest a document that would help with the words learned during the lesson

Push documents based on other criteria (not enough ratings, not high enough ratings, some sort of weighted average between who rates documents and their involvement in the language overall)

A listing of difficulty or what lessons most relate to the document

List how many people have updated/opened/completed/etc a document. It might be helpful to show the level of involvement within each article. I'm wondering if some people would be more inclined to translate certain articles if they knew how many people have previously translated the article. This was something that was visible in the beta versions.