Hmm... some of the apps mentioned have costs, some require logins, some don't integrate well with other apps, some don't exactly rock the design department. While each of them has something to love, I don't know how much real scale this "replacement" process is. B/c to get some of these great features, I have to give up confidence that it's "Apple vetted and integrated". For a techie, it's a relief to have a non-apple capability, but I wonder about the average consumer, who likes the "free, integrated, no accounts/logins required, apple-ly cute" aspects of default apps.

If anything, I expect to see things go the other way: Apple will replace google maps with it's own maps, and any other app that we really love a lot will have an Apple analog: integrated deeply but controlled by them. Siri was but the first step, I fear.