Updated with new information.
At Apple’s special education event today, one of the announcements the company made was the death of iBooks Author. Book creation has now been folded into Pages, a surprise move that actually makes sense.
iBooks Author > Pages
Creating books in Pages can be done on both macOS and iOS. You can make the same rich, interactive books as usual using a variety of templates created by Apple designers. A new feature is real-time collaboration.
You can collaborate in real-time with other people to create books together on iCloud.com, iPad, Mac, and even iPhone. Books can be shared and published to iBooks as usual. This is an interesting move on Apple’s part, and maybe it will breathe new life into book publishing in Apple’s ecosystem.
Update
It turns out that iBooks Author is here to stay, and the new eBook features in Pages won’t replace it. iMore’s Serenity Caldwell talked to Apple:
For example, you still can’t open .iBooks or .iba files in Pages. You can export a Pages-created eBook as an epub 3 file though, which is the latest file standard. Pages also can’t handle interactive eBook features like quizzes, HTML5 widgets, or popovers.
It’s possible that iBooks Author may end up getting deprecated in the future, but right now it’s here to stay.
For me the biggest thing is that two page layout is back on my iPad. I really missed that.
iBooks Author is not going away. See 512pixels.net to get more info on this subject. They asked Apple and got answers