Just from a UI/UX perspective, not sure if you care for an opinion of such; but if you do, read on.
"Lists" on the top navigation is not really intuitive to the user; possibly where it's placed and/or the label for it. The options in the top nav seem to be the most important features of your interface. "Lists" is one of them, but unless one are a registered user, "Lists" in the top nav does not allow guest users to do anything with it. It does not benefit them in any way and I believe there is sizable amount of people who are not registered and use the interface frequently, but this feature is meaningless to them, probably by design.
Secondly, even if you are a registered user, I would say "Lists" is probably not the first thing people would click on. It's a vague word and as a frequent reader (but not a frequent user who interacts with your interface), this was the last option I clicked on.
Here is my experience of it: I spent about 5 minutes trying to find where my bookmarked stuff went. I clicked underneath my username, clicked through all the options thinking it'd be there, but then it wasn't. Went through it twice, because I remember there being a page for it, since I have used it a few months back, but I don't know where. I finally clicked on "Lists" and viola. Now I know my bookmarks are safe. The only thing is, I hope I don't forget a few months later of not using it.
My suggestion is to tuck "Lists" underneath the username list of options, or the bookmarking list of options with the icon; since this is an option users can only use if he/she is a registered user. Renaming "Lists" to "Bookmarks" or something more meaningful would also help users identify and intuitively navigate through your interface. It's not a major issue, but could improve the experience of users.
