I mentioned the whole why would they lock phones now etc a while ago and a guy was adamant that every phone will be locked to each network so this means 20 different models assuming the below.
16gb black iphone (3, vodafone, orange, o2. tmobile) = 5
32gb black iphone (3, vodafone, orange, o2. tmobile) = 5
16gb white iphone (3, vodafone, orange, o2. tmobile) = 5
32gb white iphone (3, vodafone, orange, o2. tmobile) = 5
Not sure about pay and go ones as they should be included in the above.
This is what will happen. Some guy posted a screen shot from Carphone Warehouse showing separate models for Orange and O2, with the various colours and memory storage. The lock is only a software lock, so there are no manufacturing complications. I'm sure the reason for the lock is just to ensure that the network gets some kind of cash out of you for the first 12 months. I don't imagine they make very much margin at all in selling you the phone itself.