I had not thought about this before. But if Apple and Google both provide free messaging services, this could have a huge impact on phone companies. The big question is, will they make their services ubiquitous? Google would seem to be the best candidate for this. I could see them making an app or web app that would allow anyone to message on any device. I can never see Apple creating an Android app. But I could definitely see the reverse.
Report: Google eyes iMessage, readies rival service | Mobile | Macworld
Cellphone Carriers Face Pressure Over Texting - WSJ.com