We submitted the original version to Apple with a fully functioning store built into it—and were then stuck in submission limbo. Two weeks later, Apple announces their intent to build in-app purchasing.
The kicker: Apple wanted a 30% cut of every book sold on the store …and at the same time, had negotiated with book publishers that the publishers MUST sell all books at a 30% margin on ALL stores if they want to sell their books via Apple's own ebook store.
Aka we couldn't sell books at an increased cost, even if we wanted to. We would have had to take a loss on every purchase.
In the end, we had to remove all of the store functionality from the app, and weren't even allowed to link people directly to the web store for purchasing (or even instructions for purchasing).