I think Milla's "nightmare" room is definitely a nice little easter egg for most people. It doesn't actually have anything in it except the tortured souls of dead children... ! (I think the PC Zone interview/article goes some way to explain this... Pretty interesting!).
Also, surely the extra video should be added as an easter egg? If you bother to get 100 rank...
you get a nice little video showing Mr. Pokeylope and Linda (from the Lake).