For all of its past successes, Nokia hasn't played an important role in the US cellphone market for a mighty long time. Having failed to make an impact on American consumers for the last few years, the company is now making the US a key target for its new Windows Phone push, and it's putting a name on the project: Rolling Thunder. The metaphor is one of a gradual progression and buildup toward a crescendo of awesome smartphones. Follow along here as we track Nokia's progress in this bold new venture.