The Lumia 900 which features a 4.3 inch display, 8MP camera, 16GB storage, secondary camera for video calls with a 1.4 GHz processor is the successor to the Nokia Lumia 800 and is available on AT&T's LTE network.
Unfortunately there is no official release date so we have to hope that the rumoured March 18th launch date becomes a reality.
You will have to sign a two-year contract with AT&T to receive the device at the subsidized $99 price and you can only pre-order it in the retail stores as it is not available in the online stores yet.
If you are interested in getting your hands on one of the best Windows Phone out there head over to your local Microsoft Store.
source - GSMArena