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According to the AP, “software developers now will be able to create applications that have items for sale within them, such as electronic books or additional levels of a video game.” The latter idea is perhaps most interesting, as it introduces the concept of a subscription to the hundreds of popular games offered on iTunes. This allows developers to continue to offer their applications at low initial prices like 99 cents or $1.99, but earn additional revenue on the backend.
As for heavily requested end-user features like copy-and-paste and multi-tasking, as of 10:38PT, these features have not been announced according to Engadget, who is liveblogging the event.