With iWork 9.0.4, Pages becomes a DIY publishing tool for iBooks:

Pages ’09 lets you export your documents in ePub format for reading with iBooks on iPhone, iPad, or iPod touch.

Use ePub when text is the most important part of your document, for example when you create a book, a report, a paper, a thesis, or classroom reading material.

When your masterpiece is done, submit it directly to the iBookstore via iTunes Connect.

Boom.

Update: Distribution currently requires syncing with iTunes; neither Safari nor Mail on iOS 3.2 or 4.0 recognize ePub files or let you add them to the iBooks library. I’m sure this will be addressed once Pages for iPad can also export ePubs.

“Consumption only” etc.