It seems like Nintendo once again will work together with Sharp to create a free-form display for their next handheld. According to the Japanese business news paper Sankei Biz, the production will start 2016 and the screen is supposed to have some sort of round donut shape with a hole in the middle. That sounds like Nintendo alright.
This might of course have something to do with their Quality of Life program that hasn't quite been revealed yet, rather than the successor to Nintendo 3DS. Sharp already produces the 3D displays for Nintendo 3DS, so the companies have a longterm partnership in place.
Thanks, My Nintendo News.