Frankly, Blizzard is more on the ball about this sort of thing than SE has been thus far. From what I've heard, they spend months during beta prepping for launches to make it as smooth as possible.

it would be better if everyone trying to log in could get into a queue instead of continually hammering the server, both from a player and a server stability standpoint, but I guess they wouldn't be able to handle queues of the size that they would get. I dunno.