The latest tweet from WPleaker has a video demoing Cortana in action along with HERE Maps UI which he leaked earlier in an image. This time claimed Cortana reveals itself completely in the video. Don’t ask whether this is real or fake! It increasingly looks real, but can be handiwork of some smart “Faker” as well. For the time being enjoy what looks like really nice Windows Phone 8.1 concept, which will be really great if comes true.