Forrester researcher Sarah Rotman has taken a detailed look at Windows Phone and the impact the US launch of the Nokia Lumia 900 has on the ecosystem. Admittedly with a bias towards how the American market works, Rotman portrays a scene where the emergence of a third platform is not only likely, but one that many players would appreciate.

The smartphone market is ripe for disruption — Palm is dead, Symbian is sunsetting, RIM is faltering, and every player in the ecosystem (other than Google and Apple) wants a third player to wedge between Google and Apple. Windows Phone, led by Nokia, can — and should — be the market disruptor, but doing so requires overcoming two challenges.

Those two challenges are actually more to do with implementation and retail strategy rather than anything else - working with the networks and ensuring the marketing message reaches the right customers, rather than technical details on the operating system or the third party app system.

Perhaps that's because Rotman acknowledges that personally she's a big fan of Nokia's Windows Phone, and she's done her best to take that out of her analyst work. No matter, this is a strong justification of the strategy that Microsoft are taking, primarily with Nokia.