Let's consult complete list of encyclopedia topics and pull from it the topics that are the most important that we have not yet covered. Here's how I (LMS) propose that we do this. (1) Identify a broad area about which you know a lot. (2) Review complete list of encyclopedia topics (which Magnus Manske has magnanimously contributed) and pick out topics in that are, in your opinion, among the most important one-tenth of topics, and add them to the appropriate "basic topics" page.
So, why do this? To get a good idea of what blanks we need to fill in--hopefully, this will focus a good number of people on the task of writing about those topics. This will increase traffic to the website and make it a lot more useful.