However, a $300 kiosk is probably out of the realm of possibility for many one-man operations. At the same time, the business demographic to which they are appealing with this (larger established businesses that need a physically-integrated register solution) is already competed over by a plethora of companies.
The whole point of Square was to occupy the niche of hyper-small operations and forsake the market for large businesses. Not only are they competing with the established companies like Verafone, but also with the dozen or so other companies that target larger businesses with iPad register solutions. I'm not sure if they will be able to compete.
That's not to say that this will be unsuccessful. Obviously, Square has had some success in penetrating the large-business market. I don't know. Maybe Starbucks will buy 10,000 of them or something. It just seems like a more volatile and crowded market...