My iPhone updated a couple hours ago with no problems. I just tried updating my iPad, and I get the "...iPad could not be restored. An internal error occurred."
Apple's iOS5 software works just fine. Be patient - you will be rewarded.
I'm on my third try on a 3GS, same error. I would have to agree it's most likely a server error from the billions of other people trying to update their devices.
Errors in the 3200 range relate to gs.apple.com not being available; hence I'm not surprised some errors are changing to apple.com not available, and I'm not surprised its working for some people (Auth message managing to get through).
Haha how very odd. Ive been trying since around 7pm to download it, look at articles online about it then I think ill come on Macrumors to have a gander on the subject. Go back to iTunes and try - BAM! - downloading.