The iPhone is not the iPod, and the iPad is not the iPhone. So you may not get 70% by playing catch-up, but you don't always get it by doing whatever Apple does, even in the case of their big successes like the iPhone.

However, I think a good argument could be made that the first generation or so of iPods were sold sight unseen to a public with a fairly large number of mp3 players in the same marketplace. Few people remember that the original iPod was supposed to be a driver of consumers to the Macintosh platform. For a pretty long time you couldn't use one on any other platform other than a Macintosh.

iPhones sold well because the competition in the marketplace wasn't really all that great. Palm hadn't really done anything interesting in the years prior and Windows mobile has always been a joke. But remember the long lines of people trying to buy up a dozen or so iPhones at the original price sight unseen? I remember one lady standing outside a store with a stack of cash trying to buy phones off of people who got one for 2x the original purchase price.

And exactly like those two items, the iPad has people lined up getting as many as possible because their iPhones are so awesome. Even though the logic of blowing up a phone app onto a tablet makes little sense, and the iPad actually demonstrates a reduction in capability over the iPhone (no camera, seriously?).

I'd wager that it'll be just enough that people will slurp up the next version that'll have a camera and USB even though they already own the original.

The problem that people have is not that the iPad is a good product or not, it's that people are buying it without having any idea what it's like beyond "it's a bigger iPhone". If some other vendor had come out with exactly the same product, they wouldn't have flocked to it, because it's sight unseen. But stick an Apple logo on it, and have Jobs sit in a chair fiddling with it for 5 minutes, and it's sold out before it even hits the stores.