Preview at WWDC likely in June, followed by September launch.
Apple Now Including Unique Identifiers for In App Purchase Receipts to Combat Hack
One of the suggestions for a method by which Apple could improve the security of In App Purchasing was to include a unique identifier in validation receipts, and we've received word that developers are now seeing something along those lines coming from receipts issued by Apple since late yesterday. The receipts carry a new field called "unique_identifer" that appears to include the Unique Device Identifier (UDID) for the device making the In App Purchase.
As one developer noted to us, apps are no longer supposed to be collecting the UDID and thus it is unclear whether Apple's use of the identifier for this purpose is simply a first step toward a broader implementation of unique receipt identifiers for increased security or if Apple is attempting to identify those users and devices who are sharing their receipts with the Russian hacker to allow the method to function.