Glad to see I was wrong about this. I do wonder why anyone would now buy a book from Apple given that with the Kindle app you can read on multiple devices.
I do wonder if Apple will allow this for a while either as a sales tool or a test and eventually remove the app. I am sure they will be watching the number of books they sell via iBook and the number of downloads of the Kindle app.
On a related note, Consumer Reports
has a first review of the iPad that is the first non-hyped and balanced one I have seen.