It's funny to me that SE doesn't take a page out of their own history books. Anyone remember world passes from FFXI? If you don't have one from a friend, it dumps you randomly onto a server that isn't packed full. If you did manage to get a world pass from a friend, you can play on the same server as them. Also, how about opening up some free voluntary server migrations to some worlds that just opened, or aren't packed absolutely full? I'm sure plenty of people would be willing to hop to a less crowded server that way.