Lets Start a iMessage bug list LOL
1) Inconstant use of Caller ID. One minute it uses @me.com and the next it uses the other email address
2) All iDevices don't keep up to speed with messages
3) Reading message on one iDevice doesn't clear the alert, badges or missed event in the notification centre of the other iDevice
4) Sometimes when sending message in iPad the message is sent but the blue bubble gets stuck where you type the message. Only way to resolve is click off or exit (not force close) and reopen.
5) Can't add people to current conversation.