Minecraft modders HighlifeTTU and Lazertester have created a 3D central lobby system for Minecraft which allows users to walk around and explore while choosing a server to join.
The mod is a Minecraft world which allows players to connect to other worlds from within it, but also includes a relaxation lounge, closed PvP areas, other players, and even swimming pools. It is designed to bring players together into a bigger community instead of separating everyone into menus and individual servers.
Currently the mod is only available in the U.S., but there are plans to make it available in Europe and Australia in the future. You can check out more details about the mod and how it works here.