I'm afraid you're having no luck today fallout guy
If you're interested in discussing multiplayer we have an official thread http://www.gamesas.com/bgsforums/index.php?showtopic=976152. Make sure you read the opening post first as this contains some general ground rules for the thread.
Fallout 3 is a single-player only game. It is Live enabled but this is only used for achievements and downloading DLC and what not, there's no online play. As with the core Elder Scrolls series I think it's unlikely a game in the core Fallout series will get multiplayer but it's certainly possible we'll see this with a spin-off title. There are two Elder Scrolls spin-offs (Battlespire and Shadowkey) with multiplayer :shrug: