I don't recall Apple ever promising that but if they did they wouldn't have explained why they can't or won't do it because they don't want to have it both ways. They are fine saying nope it's not open deal with it. Google seems to want it both ways which puts them under the microscope. Apple gets plenty of criticism from the same types of people for not being open. I don't buy into the poor lil' Google angle of this. They know exactly what they're doing.
"Upon the launch of the iPhone 4, Jobs promised that Apple would immediately start working with standards bodies to make the FaceTime protocol an "open standard." As of November 2012, it is not yet known to have been ratified by any standards body, and the extent of work by Apple with regard to this promise is unclear as Apple has not released technical specifications for the service. FaceTime is not currently supported on any non-Apple devices."
I read somewhere that the Facetime team heard about the open-source promise when Jobs announced it on stage. It could very well have been a spur of the moment decision made on stage.
(Not that it absolves Apple from failing to do it)
