I'm not sure what issues with iMessage that others are having, but I just figured out today that none of my iMessages have been going out since Sept 28th. I have been keeping up with all of the iOS 7 updates, but didn't realize the problem till today. I just simply turned my iPhone 5 off and then restarted. After the restart, My iPhone showed that all my iMessage texts since the 28th had experienced a failure to send. Everything seems to be working fine now after the restart.