I have also activated mine.
But for me, the server problem was a blessing in disguise - the iPhone I bought originally had three dead pixels so it was the ideal excuse for me to take it back for a full refund whilst my boyfriend bought me another one. As the first hadn't been activated, no questions were asked...
So, all in all, I'm happy (and the screen on the iPhone is a lot better than my iPod Touch, too).
Although, my iPhone still says 'No Service' nearly an hour after activation even though my BF's O2 phone has full bars. I'm hoping it won't be too much longer??