Sigh. Either you haven't thought very deeply about human factors, or you're young enough that you've never had to experience any sort of back, neck, or eye pain.
I don't know about you, but when I sit and read a book for a few hours, I don't put it at arm's length on a coffee table or desk. Instead, I sit on the couch and drop it into my lap, resting my it arms. I'll switch positions around (everyone does it unconsciously) to keep from getting stiff in one position. Bring it up close to my eyes for some time, so your eyes focus at different length and don't get so tired. Handing a laptop to your friend sitting next to you, to say "Hey, check this out" is geeky and awkward. And so on.
I'll say it again, a clamshell design is a total fail for this sort of informal use. My old body starts hurting after a short time trying to use a laptop in such a way.
A phone is valuable because it's always on you, but it doesn't make a very good multitasking computer or book reader. A laptop is valuable because it's powerful, stores a lot of energy, and can multitask, but it doesn't make for a very good computer in the living room. There is an unmet need for something like that, something I really didn't notice until I had a laptop and cell phone -- which was only until very recently. For people like my sister, who don't use a land line or desktop, and multitask their computer use with everything else, it's going to be a hit. She _never_ sits at a desk to use her computer, ever. The laptop is there on the couch, 24/7.
If it's fashionable enough, Apple is going to cry all the way to the bank on this.