A player list. It's in so many other multi player games, it's pretty much become a standard. When I join a server, I want to be able to know what other people are playing with me
Maybe it's because the server software is in a bare bones state right now. It's just enough to work right now. The devs will be adding way more server features (As well as making them way easier to set up) later, when there aren't more important issues to worry about.
