The most I've heard about this device is that if it is even in production or if Microsoft and Nokia have any plans at all on a successor to the 1520. Again if all rumors are true. Then I don't know what you've read or heard, but the device is said to be headed to T-Mobile, At&t and Verizon Wireless. The specs are scarce but of all rumors put together. (Again its just rumors!) There's talk about it supporting a 2,560 x 1,440 resolution (2K.) The processor is said to be either at Snapdragon 801 or 805. camera is said to be either a 21 MP or 41 MP? As for the OS I would guess Windows Phone 8.1 update 2... Or if they make us wait long enough then possibly Windows Phone 8.2/9? I'm not sure about the battery, I'll personally guess a 3,400 mah. As for memory multiple sources are throwing around 16GB or 32GB with 3GB or RAM.
That's all I got on this subject. I currently am on Verizon with the ICON and am desperately waiting for this device to be real...... If it isn't, well then IDK. LOL Hope this helps with your question and wonders!
Chris