I love my iPad, but I think it's safe to say the sum of the parts is less than the whole. If unix is about composability, iOS is the opposite. You can get work done... within an app. Your apps will never act as a multiplier to make the device as a whole more useful though.

I guess where I diverge from the author is that I don't really think it's a problem that it's mostly a consumption device. I think desktop computers are so thoroughly better as creative devices that maybe its fine that the ipad has its own niche.