I don't think Apple can respond to an device which is basically an e- reader plus. Amazon has already won the e-reader crown. An iPad is probably least known and useful as an e-reader to most - mostly due to the higher costs of its books and lack of compatibility with not only other devices but even Apple's OWN devices. i.e. there is no Wyspersync, and no iBooks on a Mac.
Amazon truly rules the e-book world.