Right now user pictures, individual blogs (with file uploading enabled so you can always have your writing handy), buddy lists, public forums, custom groups (with customizable privacy settings) for sharing of writing critiques and files, as well as a few more features, are enabled. I'll add more features as it goes and as people leave suggestions in the forums, etcetera. Sure, most of this is doable on LJ, but I like the idea of a site just for writing and reading geeks.
Oh--here's the BookMuncher banner if anyone is interested.
If BookMuncher ends up being as successful as my webcomic, I'll be pretty happy. I had run it in a beta test for a little while, and just posted the first "live" link a couple of days ago. I'm pretty pleased by the response so far