I was pretty skeptical about Kohjinsha’s dual 10.1-incher when I first wrote about it, but it actually looks decently engineered in this video. The second display simply slides out behind the first, like on GScreen’s Spacebook and Lenovo’s W700.
https://gizmodo.com/kohjinsha-netbook-concept-has-dual-10-1-inch-screens-5375159
It’s slightly thicker than a normal netbook, but the insides are pretty much the same: Windows 7, 1.6GHz AMD Athlon Neo MV-40 processor, maximum 4GB RAM, and 160GB hard disk. How battery life would be affected remains to be seen.