There is allready a multiplayer mod for Skyrim availlable with which you can play The Elder Scrolls Skyrim online. It is still in its alpha stage, but it is allready possible to see (as a spectral horse) and chat with other players.

Take a look at http://www.skyrimnexus.com/downloads/file.php?id=3592 to download the Skyrim online multiplayer mod and for more information.