Originally Posted by Our Lord and Master, Apple
No more Lite version - Mentioned in the announcement itself, developers can now (if they choose to) package their whole app under a free title, letting you try it, then if you want to really get it, just unlock the full game/app through an in-app purchase.
The end of piracy? - Probably not, but it'll be harder now. Since in-app purchases are verified through Apple to check that your account has in fact purchased the feature before being unlocked, you won't be able to just find a cracked .ipa and call it a day.
NO MORE "FREE 40 PRESTIGE POINTS IN HAPPY MMO FUN KITTY TIME" littering the free section of the store - Developers for these MMO games can now "sell" these through the app itself.