Alice in Wonderland for iPad. When we talk about iPad and the future of print, this is what we mean, not some gimmicky scrolling UI.
Update: Ok, so I've just downloaded it ($9, or a free lite version with one chapter), and this is not entirely what we mean when we talk about the future. The best way to think of Alice for the iPad is as a digital version of a pop-up book. Mainstream book publishing isn't any more likely to make all their books like Alice than they are to convert all their titles to pop-up format.
But it is a very nice e-book. Kids will love it. By the way, check out the gorgeous paper version, too.