This is probably a first in the MMO industry... EVE Online announced higher performance server reservations for large scale PvP battles. Unlike most other MMO titles where you choose a server to play on with your friends, EVE Online doesn't make you choose. Although the server cluster is made up of hundreds of IBM blade servers, from a player's perspective, it's all one galaxy with over 5000 solar systems. This is good for a 'sandbox' game, where players are allowed to do whatever they feel like within the rules of that place. It creates a huge galaxy where everyone can potentially interact... or kill each other. But it comes with a rather substantial drawback at times: lag.
This 'single server' approach makes EVE Online a game where players hope to have large-scale fleet battles not unlike all those sci-fi shows and films we grew up with. But the harsh reality is that there are limitations of server technology that hinder large scale conflicts. Bring a few hundred of your friends to a fleet battle in EVE and you might not be fighting so much as watching a slide show. Definitely not the most fun to be had in the game.