My objection here is that Apple is excluding everyone who is too poor to afford a Mac. Yes, you can get a Mac Mini for around $600, but I know lots of teachers who cannot afford it. I can't, either.
But at lest this app promises ease of use. You're going to be able to drag and drop photos, videos and even Pages or MSWord files into various stock templates. It's also going to be easy to add a add a cover and TOC. Building glossary is going to be a 2 click operation. The iTunes listing also says that you can interactive widgets. For example, you can drag and drop a Keynote presentation into the doc and it'll live on as an interactive widget.
Still I think this really should have been made open to teachers everywhere, including the ones who are using old computers, hand me downs, and even borrowed equipment. Education should be democratizing, not just open to the wealthy.
BTW, if you're noticing that I didn't fault Apple for the iTunes U app, it's because an iPod Touch can be had for considerably less than a Mac. Also, I think creation tools are a separate case from the apps that use the content.
Update: And I've just heard that this app actually makes Epub which can be read on other devices like the Nook and Sony, so there's a really good reason to make it available to all, not just the rich. And the license restricts you from selling the ebook elsewhere, but that's just icing on the cake.