If you still have error 3200 and the servers are still too busy you can trick around.
Usually the apple server needed to be contacted is gs.apple.com, some of you already know this NAME by editing their hosts file to redirect gs.apple.com to a saurik server to skip authentication.
The official ping -a result of gs.apple.com ends in a 17.11.x.x IP range, thats the too busy one.
The redirected gs.apple.com of saurik goes to 74.x.x.x IP range or similar but this does not register your iOS5 successfully.
But apple has a kind of "hidden" gs.apple.com also that is passed by their dns resolver, and this one was fine yesterday evening with a ping of 32ms and made the update within 1 attempt.
Short, edit your hosts file, uncomment all existing gs.apple.com redirects and add
(How to do this read on page 18 in my previous post, do not forget to reboot to get it active for iTunes)
Hope you all get iOS5, its nice