The new app looks to function much like Inkling's original iPad app, and it can be used to read the same textbooks you've already purchased in your Inkling account. The app will also let you download the textbooks a chapter at a time, and given the hefty size of some of these works that's a feature I can appreciate.
This doesn't bode well for the iPad as the future of education, does it?
Between Kno adding a Facebook app for their textbooks and now Inkling offering both an HTML5 app and an iPhone app, it would seem that there's more to the classroom than the iPad. Even if you set aside the fact that only a small minority of students in any given classroom have an iPad, it seems likely that the iPad costs too much for it to be practical for a significant number of students.
So if any textbook distributor wants to get their platform adopted on a large scale they'll need to support more than Apple's $500 tablet. And large scale adoption is the wet dream of every digital textbook distributor, for obvious reasons.