My iPhone 5s downloaded it then started saying "preparing update" for like an hour, but worked.
My iPad is saying "Update Requested" and just won't do anything, so maybe they've implemented a queue system to leave bandwidth for other people? I don't mind not updating my iPad just yet, not in a hurry, glad I got my iPhone updated ASAP though.
It'll notify me when it's downloaded to my iPad anyway so I'll just wait until then.