This is the Windows Phone that could turn the tide for Microsoft.  Aaron reviews AT&T's Nokia Lumia 900, and at $99.99, it's planning to compete out of the gate.  Featuring a 1.4 GHz single-core Snapdragon CPU, Lumia 900 offers a 4.3-inch AMOLED display with ClearBlack technology, 8-megapixel camera with 720p HD video recording, a front-facing shooter, 1,830 mAh battery, 4G LTE connectivity, and Windows Phone 7.5.  Is Nokia back in a big way in the US smartphone market?  We'll find out.  Part 2 of 2.