It just happened to me again. I intentionally powered on my unit the night before going to a trade show and forced any updates available. When I set up at the show the next morning it had an update with no option to skip that I had to wait through. I'm just glad I got there early enough this time so no customers were left waiting.
While there isn't a way to do this that I know of I can see how that would be a great feature to have.
