It was on the iOS 5 wishlist too, but what did Apple do about it? Zip. They shot themselves in the foot about that - I've deleted the iBook app to stop it being the default "open in" app, and I know quite a few other people who have done the same.Not as far as I am aware. The last apps installed that are capable of "Open in..." will bump older ones off the list.
Something to add to the iOS6 wishlist.
Is there a more efficient way of having certain apps showing in the "open in" process other than deleting apps until the one(s) one wants listed in an app?
it doesn't.Perhaps this may help How To Use Open in... on the iPad | Mac|Life