I've always been leery of the laser keyboard due to its lack of tactile feedback, but I don't think it would be worse than a touchscreen. Given the screen real estate this would free up, it might be a good trade.

Barring that, it's tough to imagine why I would want one of these things, slotted as it is between an iPhone and a laptop. It would have to be good enough to replace the laptop, at least for lightweight trips — overnight business trips, coffee shop visits, and the like — and have unbeatable battery life, maybe eight to ten hours of real-world use. Without those things, it's tough to imagine why I'd want one. But Apple has (positively and negatively) surprised me before.