All online games have the same problem – at certain times there are more people who are trying to play than the servers can handle. For the past 20 years, this has meant queues to wait or simple denial of service. This is also directly linked to the artificial surge in servers at launch, then empty servers 2 months down the road. People are just driving by.
Star Trek online used a dynamic environment for loading the game client but not for the login server. Which is kind of weird actually. There were dozens of game instances but you had to wait to have access to them.
TERA is going to try something a bit different. Queues will remain but you’ll get an experience boost based on the amount of time you waited. This is a tricky balancing act but a neat idea.
Guild Wars 2 is trying something completely different. If your server is overloaded you’ll be given the choice of loading an overflow server to play on. Same thing as a normal server, just people from around the world on it. Once your server is up, you get prompted to swap over. This allows developers to set up extra servers at launch and take them out when the initial surge dies. Smart move.