It's not just RIM that Apple surprised with the new iMessage instant-messaging feature for iOS devices, announced during the Steve Jobs WWDC 2011 keynote yesterday. According to Daring Fireball's John Gruber, his sources say Apple's carrier partners were blindsided by the iMessaging launch too.
His "well-connected" informant says the carriers only found out about iMessage when Jobs revealed the new service on-stage. It could well have significant implications to carrier revenue, too; while iMessage does use a data connection, potentially adding to the amount of data allowance each user will require, it could also significantly reduce SMS and MMS use.
Both messaging services are still huge cash-cows that the carriers have been used to milking. While third-party apps for iOS (and other platforms) have eaten into those revenues, Apple's homegrown functionality - which will be an integral part of iOS 5, and thus hit the iPhone 3GS, iPhone 4, iPod touch 3rd/4th-gen and the iPad/iPad 2, will be far more broadly adopted.
Gruber himself says he will be canceling his SMS plan as soon as iMessage is available, and he's unlikely to be the only person thinking that way. iOS 5 ships this fall.