Yes, that sounds very cool and if I was a mass transit commuter I might think about it. But the problem as I see it is if you're using it to browse the web (many more page refreshes) the battery life is going to come way down, right? And if you're using it to browse the web the B&Wness of it is going to get really old, really fast. Look at the simulated picture of the NY times on the screen, that's pretty limited gray tones in my book. And it's probably not going to play nice with dynamic content like flash, YouTube, ect., right? So even if it has free unlimited web access I don't see them being able to use that as a big selling point or to justify the price.
I guess what I'm trying to say is that I think Ed's original comment, that $400 is too much, is right on the mark.