March 6th is the official street date, but you can lay down your money for Motorola's modular smartphone right now, as the Atrix 4G and its suite of incredible Webtop docks are now available for pre-order. $200 buys you the biometric HSPA+ smartphone on a two-year contract, and it'll cost you an additional $300 to turn it into a portable netbook of sorts -- though as we feared, you'll need to pay $45 a month for the DataPro 4GB + Tethering data plan (on top of your phone