In an interview with CNBC, McGraw-Hill's CEO confirms that their textbooks will be on the Apple Tablet and it will be an iPhone OS based machine. When asked about their textbooks being on the Apple tablet, Terry MrGraw responds (2m 50s):
"Yeah, Very exciting. Yes, they'll make their announcement tomorrow on this one. We have worked with Apple for quite a while. And the Tablet will be based on the iPhone OS and so it will be transferable. So what you are going to be able to do now is we have a consortium of e-books. We have 95% of our materials in e-book format. So now with the tablet you're going to open up the higher education market, the professional market. The tablet is just going to be terrific."
Article Link: McGraw-Hill CEO Confirms Apple Tablet, iPhone OS Based, Going to Be "Terrific"