iBooks Author is now in version 2.2, and it's still the product to beat, despite Amazon's new Kindle Kids' Book Creator, and, more recently, Kindle Textbook Creator.
The overall strategy for all three products is to simply the process of moving from standard files authored in Word, Pages or Adobe Acrobat to eBook formats that mimic the open-source ePub3 format. Authors can easily import, lightly edit and publish their files to the respective Apple or Kindle platform, and then sell, sell, sell.
Truth is, Apple's iBooks Author leaves the Kindle software products in the dust in terms of functionality. Once you have your text in iBooks Author, it's easy to add interactivity and multimedia elements. Kids' Book Creator allows you to add "text popups", making text on the page easier to read through magnification, but that's it. And Textbook Creator has NO added functionality other than adding or deleting pages: you simply import your pdf and publish to the Kindle Store. It is only in beta version, but let's hope for more in the polished version.
There ARE ways of creating enhanced eBooks for kids and students outside iBooks Author and the new Kindle tools without having to grant Apple or Amazon exclusive rights to your content, and I'll be addressing this in the latest version of Your eBook Survival Kit, now in development. (pssst... owners of the current version will get the update for free!) The Kit is available in our new online Store.