It’s mostly been assumed that the iPhone SDK’s omission of terms enabling VoIP over 3G was prompted by Apple bowing not just to AT&T’s bandwidth concerns, but by concerns that 3G VoIP would make calls and minute moot.
It now looks like that assumption may have been unfair: Apple has just updated the terms of the iPhone SDK to allow VoIP calls over 3G. iCall is the first company to be jubilantly crowing that their free VoIP app has implemented 3G VoIP, but others (hopefully Skype!) should be soon to follow.
That’s not to say that VoIP 3G will work universally — T-Mobile in Germany, to my irritation, doesn’t allow VoIP over 3G — but it’s nice to finally see this functionality hit the iPhone after a couple years wait.