I'm not sure if or how this is doable, and there are other issues on the site to work out first (and keep in mind I'm a lawyer not a webdev by trade, so this is not my core strength), but would you guys like the ability to have personal bookshelves on the site?
Ideally, I'd find a way to integrate Goodreads or something similar, or at least replicate the functionality, so that you all could "check in" to the books you have/have read, and discuss/comment on them.
This is more of a long term thing, but I'd like to know if it's a worthwhile addition, so if that sounds of interest speak up!