http://www.theverge.com/2015/10/6/94...e-release-date
...Panos Panay introduced the Surface Pro 4 by reminding us how transformative this line of devices has already been: "This challenge of the tablet and the laptop... which do you buy? Remember that problem? It's gone." There's a fingerprint sensor on the keyboard and Cortana integration inside the new tablet, which fits a 12.3-inch display in the same physical footprint as the older 12-inch device. The Surface Pro 4 is therefore compatible with existing keyboard accessories, though Microsoft has done a ton to upgrade its keyboard covers this year. And yes, there's an all-new Surface Pen as well, which also has an eraser on the end of it. The new pen has 1,024 levels of pressure sensitivity and attaches magnetically to the side of the Surface Pro 4 when not in use. It comes in a variety of colors and even has Cortana integration: you can activate Microsoft's voice assistant by holding the button on the stylus...