What features would a unlocked iphone lose?

[Aea]

There's a guy on another forum who wants to buy an iPhone to use in Australia, I'm thinking that he'll lose out on some features tied to AT&T and have problems with updates, etc. Am I right or is there really nothing to lose but a warranty he wouldn't have much use for anyway?

[jav6454]

There's a guy on another forum who wants to buy an iPhone to use in Australia, I'm thinking that he'll lose out on some features tied to AT&T and have problems with updates, etc. Am I right or is there really nothing to lose but a warranty he wouldn't have much use for anyway?

If he unlocks it he will loose Visual Voice Mail. Also he won't be able to updgrade to future versions (just to play it safe).