Revealing mistake: After the Doctor deactivates the signal hiding the Dalek fleet, when the camera zooms out to show the ships, the background image of the Horsehead and Flame Nebulae is cut off a bit below where the Dalek Emperor's flagship is shown, revealing the end of the picture they used for a background. (00:39:00)
Revealing mistake: When the Gamestation's transmissions are cut off by solar flares, there is a close-up of a screen going over to static. In the upper right corner, a box with "Play" written in it is visible, revealing the image on the screen as a video. (00:34:50)
Chosen answer: No, no information is avalible for the identity of the entity.
Repo_Man