iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
iOS 6 Fixes iMessage "Bug" that Sends Texts to Stolen iPhones
TheNextWeb now reports that that iOS 6 resolves this issue by forcing all devices to re-enter credentials if your Apple ID settings change.
According to a source with knowledge of Apple’s steps to correct the matter, the issue has been fixed in iOS 6 through a variety of checks placed on iMessage. The most important of these is that Apple now uses its push systems to force a user to re-enter a password to use iMessage once your Apple ID credentials have been changed.Now, if your iPhone is stolen, simply changing the password of your Apple ID will force the stolen device to prompt for a password in order to continue receiving and sending iMessages from your account. In addition, wiping your iPhone remotely using Find My iPhone will now disable the stolen device from receiving iMessages.