In a recent update to the documentation for iOS 5 (which is only
available to registered Apple developers, but a copy was forwarded
to me), Apple notes that it will be phasing out access to the
unique device identifier, or UDID, on iOS devices such as iPhones
This is a big deal, especially for any mobile ad networks, game
networks or any app which relies on the UDID to identify users.
Many apps and mobile ad networks, for instance, uses the UDID or a
hashed version to keep track of who their users are and what
actions they have taken.
My guess: Apple is doing this so they can further promote iOS as a secure and privacy-protecting platform. What are the odds that Google would ever block Android developers from accessing unique device IDs? This is going to result in some work for developers far afield from ad and game networks, too, though.