A ballpark Wii U powered handheld with an Android based OS for mobile integration and detachable controllers. Packaged with a Chromecast style HDMI WiFi dongle to beam an image to a TV Screen.
Why is it taking Nintendo so long to announce this device? They are waiting for the games, of course. Both for the handheld and mobile games which will interact with each other.
Because that would be a massive disappointment. Please no.