While the Ishi format didn't take off (as a testament to that, I hadn't even heard of it before), other things did develop. The compuer is the primary conduit through which I get game reviews, though I certainly have my share of books.
I don't really care if the iPad goes the way of the dodo (I have a love-hate relationship with Apple), but I just don't think it will be inconsequential in 10 years. Look at the iPod--its current iterations (of which the iPhone really is), are extremely consequential: if it isn't an iThing, it will inevitably be compared with one.
But, to the extent you imply or assume that e-books will not replace books anytime soon, I agree. The market for e-books is still much smaller than people realize, given the limited population that own the devices. The medium's development has already taken several unexpected twists and turns, and I'm sure there are several more to come.
Finally, hey, I really enjoy my new device and the SmartGo program, so I'm going to express that. I never intend to rub anyone's nose in it, or communicate some notion of superiority. Just like I really enjoyed my first computer (an XT with PC-DOS) way back when.