On last Sunday's talkcast, we all speculated on the situation behind Google's voice app using undocumented API calls on the iPhone. Either Google just went and did it themselves, or they got special permission from Apple to dive into places that most developers aren't really supposed to go. And it turns out that the former is true: Google says to CNET that, yeah, they used undocumented APIs. What are you going to do about it?
They're not using private frameworks at all, and apparently Apple isn't even part of the situation -- Google's engineers just jumped on some extra, undocumented features in the API. The danger here for most devs, apparently, is that if Apple changes something in the undocumented stuff, it'll break the app. But Google seems unconcerned -- they have the resources, apparently, to change things if needed.
As for Apple themselves, my guess is they'll do what they've been doing: stay hands-off until a smaller developer breaks something really important. If anyone is going to get special permission to bend the rules, it'll be Google, and given that Apple's API agreements are something they can choose to enforce (or not) as they see fit, Google likely has nothing to worry about.