It seems like one of the few places where the whole experience of the iOS breaks with the simplicity of the user experience.
It's a really unusual Apple move, perhaps now that the user is already educated about using the iPhone in general, FaceTime is a good way to educate users about the difference between 3g/4g/wimax and wifi.
If this is strategic and Apple is taking on the challenge to educate users about wifi now. This has perhaps two implications (one a hopeful stretch and one pretty clear)
- This is a preemptive strike to help their users deal with the end of 'unlimited' data rates in a productive fashion.
- (the hopeful stretch) Users will soon be able to synch to itunes when connected via wifi (to keep datacosts down) they couldn't really offer that service and explain it will until their customers understood the difference between wifi and 3g.