Paypal has an Iphone app, and they don't pay Apple a royalty.
I don't see why Bitcoin apps wouldn't be allowed when Paypal is.
Well, that was kind of a joke.
The last I saw from piuk was Apple had referred him to their legal dept. to learn something to the effect of how the app needs to be legal in all areas it was being offered.
I wouldn't be suprised if Apple saw how an attack to get bitcoins exposed holes in Linode, maybe Apple is trying to avoid iOS from being a similar type of target (i.e., new vulnerabitities exposed after hackers looking for bitcoins become highly motivated).
I'ld like to see some bitcoin app become so popular where hundreds of thousands of iPhone users go to jailbreak because the app isn't allowed on the App Store. Apple might rethink their strategy then. Maybe SatoshiDICE or something like that ends up being the driver to cause that to happen.
There's always the FTC AntiTrust laws -- maybe Apple is doing this to keep competition for their payments system at bay.