The hat trick with an Amazon tablet will lie not with whether Amazon can offer a device that integrates its storefront and services--that's an easy bet, and a foregone conclusion given its history with Kindle e-readers. The real question is whether the company can produce a tablet with an interface that's natural, visually pleasing, and functionally spot-on for how it will be used by consumers.

Apple, on the other hand, has been a master of interfaces--it designs its software to work smoothly with its hardware. And it does so with an unmatched attention to detail.

Clearly, part of the iPad's success can be credited to the clean, easy-to-use interface of the tablet's iOS operating system. That iconic operating system had years of incubation on the iPhone before it graduated to tablets.

Again in contrast to Apple, the Android user interface still feels as if it's in its infancy. Maybe it's good that Amazon has reportedly chosen to follow its own path, with its own customized interface built on top of the Android OS. But that's a big maybe.