Penguin's ability to look forward and move towards interactive books are one of the many things about the iPad that many of us who believe the iPad is a great step forward knew. It is too bad that so many people have no imagination and are locked in their old thought patterns of what a computer is. The iPad "fail" mentality took me by surprise, but what Penguin sees in the future with the iPad is why it will be soon seen as very useful, fun to use, and even magical.
Personally, my iPod Touch very quickly showed me how great a touch system of interfacing with a computer can be. After getting the touch, it was only a matter of days before I wanted the same thing with a large screen. I've wanted a tablet type of computer since the days of the Newton, which was good for its time, but so primitive compared to the way computer's have evolved in the last decade.
From what I've seen on the web in recent weeks from many others in many industries expressing their thoughts on the possibilities of the iPad -- photography, movies, other forms of entertainment, various areas of science, etc., a lot of people see the future in this way of interactive programs, "books," various types of media of all kinds, for entertainment, instruction, etc., there will be a really fun future in all these with the iPad. I've been working on a couple books in the geology field that were going to be minimally interactive using the hyperlink capabilities in pdf files, but Penguins efforts have shown that my initial thoughts about the iPad were correct and what I wanted to do can be done even better than I'd planned.
Have fun!