Apple are holding an event next week to discuss the introduction of in-app subscriptions within iOS 4.3 - the flip side of this? They also intend to introduce the next-generation iPad at the conclusion of the event.
Rumor has it Apple will use it's "one more thing" at the end of the event to announce the iPad 2, something they're famous for. Apple's new in-app subscription feature debuted with the launch of The Daily for iPad. iTunes chief, Eddy Cue, declined to comment on whether the functionality would make it to other content providers and developers - he did say Apple would provide more details in the near future.
An event for iOS 4.3 could be the perfect place to do so.