This sounds more reasonable than Apple's official line that they only "break even" on the iTunes store. (Link)
They've also claimed that they don't make much money on their App Store either... Quote: "...Peter Oppenheimer added, �We run the App Store just a little over breakeven,� implicitly making the case that the App Store was not a big profit generator for the company." (Link) This seems incredibly implausible... if they've paid $2.5 billion to developers, that means they've kept just over a billion for themselves. There's no way it cost them a billion dollars to run the App Store...
I say their official word is hogwash. This story seems much more plausible.