Just want to point something out that I think some of you are missing here.. BioWare is doing this so they can monitor server performance and ensure a smooth launch by doing the early access in waves.
The assumption is that every person who is getting access today will be able to log on the moment they get the email. Keep in mind, people have jobs, school, other commitments that will not allow them to jump right online the moment the email comes.
So realistically I don't think there will be as many waves in one day that everyone is hoping for.. It's all about timing and patience.