Why, then, can the servers not handle the demand?
If there's one day of the whole year where uptime is most important, it is today. At the moment, I -- and many others -- are stuck without a working phone at all. My first generation iPhone has been reduced to an iPod Touch. The Wi-Fi still works, and can access the Internet and download e-mails, but it won't do anything but make emergency calls.
My new iPhone? It still won't activate. After three solid hours of continual attempts to activate it, I keep getting the same server error. And since it's not activated, it doesn't work. I can only make emergency calls.
Now, I always have access to other phones, so it is not like I'm completely without the ability to communicate. But many, many iPhone users likely have just one phone. If theirs is bricking like mine is, they're pretty much unreachable.
Here's one solution. You can pull the SIM card out of your new iPhone, and put it in any other AT&T phone (except your previous iPhone), and it will work. I was able to put the new SIM into my N95, and called my standard number. The N95 rang.
Of course, then you'll be unable to activate the new iPhone until you put the SIM back in.
In the meantime, Apple, you've failed your customers in a big, big way. About the only thing you've succeeded at was to create hundreds of thousands of frustrated and despondent people.