Working in IT and seeing first hand how many resources were being poured into the problem, I had no worries about doomsday scenarios. All of the critical systems were fixed first, and after that it was just a matter of cleaning up the rest of the spaghetti code. I still ended up sitting in the server room watching the clock tick over to appease my boss' paranoia even though I knew it was a waste of my time. I'd already tested it myself and validated that the patching was solid.