The old school WoW'ers are laughing at you all pitching fits right now. the first 8 MONTHS of WoW were plagued by constant server downs, restarts and glitches. Know how I remember? I'm olllld, and I was laughing on Gilgamesh server in FF11 at the time.
They do not want to make new servers until the "bloat" dies down. Otherwise they'll have empty servers when all the fleeting window shoppers decide to go back to whichever MMO they normally play. Those players are "Bloat" and if too many of them leave the same server, you'll have ghost towns and people complaining about not having any people to play with.
This is one of the reason's other MMO lose traction so soon after release. they make a bunch of new servers to kill the queses, then two months later everyone hops off to play something else and the 70 people who still play on it rage about how the MMO is a graveyard of fun and the dev's suck.