Its been a couple hours and it looks like people are already having issues with iOS 6. This is pretty normal to have issues with a new os, but the update seems to have problems all acorss the board.
At the moment Wi-fi issues seems to be the biggest problem acorss the board. At the moment iPhone 4, 4S and third-generation iPad to iOS 6 and can no longer access Wi-Fi. I wonder Apple checked the update on all possible devices.
To find out if others are having the same issue checkout the messages boards here