Penguin are releasing the paperback edition of The Sending on April 24th, so if you didn't manage to get yourself a copy in its large format - and are having trouble tracking down a copy right now - the wait will be over in 10 days.
Have you been having trouble getting a hard copy of The Sending?
Penguin has posted a news item on their Penguin Teen Website concerning the release date of the Red Queen.
The Sending has now officially been released since Saturday!