Apple announced a new iBooks Author app today, a tool for creating multimedia books for the iPad. I haven't yet had the time to properly look at it, but what I find most interesting is the integration with the iBookstore, allowing you to sell or freely distribute the books you've created.
One of the criticisms of the iPad when it was first announced was that it was primarily a 'consuming' device - for watching videos, playing games, reading books and browsing the internet. This was partly refuted through Apple's suite of creation tools - Pages, GarageBand and iMovie, which are also available as iPad apps. However there's still a big divide between the 'professional' content you can buy on iTunes, and the content that users can create themselves.
Whilst there are plenty of apps created by bedroom developers and one-person companies on the App Store, there isn't currently a similar flood of non-industry-produced digital content on iTunes.
If the new iBooks Author app allows authors and content writers to easily publish their books, then perhaps Apple will soon also do the same for GarageBand and iMovie, finally bridging the gulf between amateur and professional content.