I don't think the people who are raging fully understand the numbers involved. They have become inoculated to words such as Million, Billion and Trillion.
It is estimated that between 2.5M and 4M people have pre-ordered the game.
Thats between 2,500,000 and 4,000,000 people that will try to log in world-wide. There are estimates of U.S sales ONLY of 1,500,000 for pre-order alone.
When WoW launched they had approx 280,000 for launch day. (Thread lists Blizzard source post)
When Rift launched they claim to have had 1,00,000 go through their early access total worldwide. So the U.S pre-launch population is clearly larger than the world-wide server launch of rift.
I am sure the actual game servers will handle these numbers, the question really comes into play are the authentication servers and how they would hold up. Which in turn can really upset players. Feel a bit for BW since it was pretty much a catch-22. I honestly think people would be more willing to over-look HOW people got into EGA but would not overlook the fact if the game kept crashing and lots of server problems.