For what it's worth, I did a detailed analysis of what it would mean for Apple to "re-invent" print media in digital form, concluding that Apple has three key things going for it that make it a natural:

1. A pre-existing 50M device footprint with the iPhone + iPod Touch that provides leverage for a new device;

2. A proven dynamic platform (read: integrated hardware-software-services-tools) for end-to-end content creation, application development, distribution, and global reach, supported by deep application and media libraries, and a robust runtime space;

3. A durable billing relationship with consumers to the tune of 100M credit cards on file (iTunes + App Store, Mobile Me).

Plus, the history of Steve Jobs dating back to Next suggests that this is strategic to him (and thus, Apple), something the post covers:

Rebooting the Book (One Apple iPad Tablet at a Time)

http://bit.ly/zOoEu

Check it out if interested.

Mark