According to Google I/O, Android M supports Bluetooth Stylus support. Which means you can virtually write on anything, using a bluetooth stylus, which will ultimately be digitized on your Android Smartphone.
For instance you are drawing a vector image on your notebook or whiteboard, and you want it to be saved simultaneously on your Android device, probably a bluetooth or wireless stylus will help you out, if you are upgraded to Android Marshmallow or Android M 6.0. So this adds a tremendous help for those graphic artists who do not want to work twice. We can expect this great feature to be the part of latest Samsung Galaxy S7 or Galaxy S7 Edge Smartphone.