I think they wouldn't sell too well. For the collectors they'd be great, but most of us don't want to pay quite a bit of money for something that's outdated. And knowing apple, they wouldn't be cheap.
What if when you looked from the front it looked exactly the same as one of those early macintoshes(the one piece screen with floppy drive underneath) but it was LCD screen thin so you could easily move it or even fold/slidel a keyboard out from beind(like a new slider mobile phone) -that would be good, a laptop with a decent sized keyboard