[neonfunk]

Background VoIP support in iPhone OS 4 suggests Apple has no intention of blocking these apps; in fact, it seems that they're encouraging them. And as I understand it, G Voice is not a VoIP solution yet. (And that's not to say I agree with it being blocked. On the contrary, their UI — the supposed rejection reason — doesn't look much different from the other dialer apps, including Skype.)

As far as "competing VoIP solutions", it's not like Apple is competing in the VoIP arena; they seem perfectly content to let other companies battle it out.