Server Structure in EVE Online
Massively takes an interesting look at the server model used by EVE Online. It's unusual for a MMOG because it doesn't divide the player load among different servers or "shards." Instead, the same cluster handles the entire EVE universe and all 300,000 subscribers (total; record concurrent load is around 40,000). The EVE Dev Blog recently announced some upgrades to keep things running smoothly and allow for battles involving over 1,000 ships. They call the technology StacklessIO.
While I personally don't find Eve the game to be very entertaining, I love to here any new information about it. That's partially because stories like this can only come out of a game like Eve, but also because it's pretty much the only MMO right now that's really doing things their own way and not just following in the footsteps of WoW and Everquest before it.