Beware: if your iPhone gets stolen, it will keep receiving messages sent via iMessage even after a remote wipe out and deactivation. The thief—or whoever buys the stolen terminal—would be able to read whatever is written to you.
Users in Apple support board are reporting this problem which has no solution for now. The iMessages will arrive both your new iPhone and the old one. One of the users says that the only way to solve the problem is by canceling the old Apple ID and creating a new one. [Ars Technica]