Nokia Lumia 810 now free on T-Mobile's website with signed 2-year pact
pixel density of 217ppi. Driving the device is the dual-core 1.5GHz Qualcomm Snapdragon S4 Plus MSM8960 processor with the Adreno 225 crunching the graphics. 1GB of RAM is on board and 8GB of native storage is included. This can be expanded through the use of the 32GB capacity MicroSD card. The 8MP shooter on back captures video in 1080p at 30fps while the 1.2MP front-facing camera is adept at snapping self-portraits. The 1800mAh battery can be recharged wirelessly if you pony up for the optional wireless charging kit. Nokia Drive allows you to hear free turn-by-turn navigation with traffic alerts and speed limit warnings for up to 166 countries and 50 languages. Nokia Transit gives you info on public transportation.
The difference between the Nokia Lumia 810 and the Nokia Lumia 820 is the lack of LTE connectivity on the Lumia 810 (no LTE for T-Mobile, of course), the slightly larger battery on the T-Mobile model (1800mAh vs. 1650mAh), and the larger capacity microSD slot on the Nokia Lumia 820 (64GB vs. 32GB). There is also a difference in the sensor on the front-facing camera which is 1.3MP on the Nokia Lumia 810 and .3MP on the Nokia Lumia 820.
source: T-Mobile via WMPoweruser