Looking through the talks from the Game Developer Conference 2013, aside from the new excitement about virtual reality (again) and several talks about cloud computing, there was this very technical talk by Joe Rumsey from Blizzard Entertainment about Network Serialization and Routing in World of Warcraft. Slides available from his blog. This talk goes through the issues of building a very large distributed server backend that necessarily supports a variety of protocols and where compression is a worry simply because of the scale of complexity involved and the need to communicate with clients.