Amazon appears to be the firm doing the most sophisticated job of engineering an instance of the new species of operating system. They just released the API for the payment component. This component weighs in at 260 pages.

Some of what they have put forward, e.g. the historical pricing or the access to Alexa data, are perfect examples of how these OS will leverage getting close to unique resources that the hub vendor has aggregated – i.e. these are vertical in the sense that they leverage unique supply side advantages.  Others like the storage and compute offerings are perfectly horizontal.  The payment’s offering, while principally horizontal, a bit of both.

Clearly some of these are more strategic than others.  I’d love to see their road map and to understand better the cross API synergy and lock-in.  I presume there are people at eBay/paypal, Google, Microsoft, and Yahoo thinking a lot about those.  If I were them I’d hope Walmart buys Amazon.
It is looking risky to be a hub vendor who just sell bandwidth, hosting, payments, what ever.  It is interesting how quickly these hubs are threatening each other’s survival.