I love the idea of having a phone that folds out to form what is effectively one large screen. For two-screen viewing, I would have liked to see it work in landscape mode with the dead space running horizontally across the middle rather than vertical.
One concept that I think could be really useful in future phones is dual layer screens. A transparent E-Ink screen overtop a AMOLED/LCD. For text reading and simple cell phone duties; it turns off the Color Display and utilizes the E-Ink display. When media functions are needed, it switches to the color display.
NEC Medias W features include a pair of 4.3-inch LCD displays (each 540 x 960 in resolution), a 1.5 GHz dual-core Qualcomm Snapdragon MSM8960 processor, 1GB of RAM, an 8-megapixel shooter, 16GB of built-in storage and a micro SDHC slot, WiFi, Bluetooth, GPS, 2,100 mAh battery, LTE Connectivity. NTT DoCoMo Medias W N-05E will be available from April,2013 in Japan.