Difference in network locking and software locking
Maybe I've got this wrong (please correct me if so), but in the UK, mobile phones - generally - start off simfree, and it's the networks who buy their allocation, lets say from Nokia, with firmware locked to the network.
Even when a network operator has an exclusive deal on a phone, it's only Country-wide - there's plenty of simfree / other network phones knocking about elsewhere in the world.
In this case, Apple are releasing a phone that only works on O2 - there isn't a simfree alternative like there normally is with other phone manufacturers. You can't stop Apple doing this, nor can you insist O2 provide an unlock code at any point - it's not their software to unlock.
The point I think I'm trying to make is that - in the UK - networks are only obliged to unlock a phone for you when it is their request that locked the phone in the first place. Apple are not a network operator, and if they choose to release a phone that just so happens to only work on one UK network, who can do anything about it?
From what I can see, Apple are under no obligation to support phones that O2 unlock for their customers in 18months time, because all O2 can do without an official response from Apple is provide the same JailBreak type method currently used by all those pesky hackers - and there is no legal obligation for Apple to do this.
Soooo, assuming I'm not talking utter pap here, O2 may well be unlocking phones for customers in 18months, but they can quite possibly do it with a smile knowing you'll be bricking it the next time you run an update with official Apple software.
I think I lost my flow about halfway through that...damn you perfectly chilled SanMig!