So...here goes again.
I really love how Rory and Amy's relationship has been progressing. The Doctor has caused a distance to grow between them, but at the same time he has pushed them closer together. If the Doctor had never returned and taken Amy away, she would have spent her whole life pining for the Doctor and never able to be with Rory in the way he wanted. It's still complicated and I think that will be shown in the episode, but in her adventures, Amy has truly realized how much she loves Rory (despite the Doctor rape).
Now! Onto my main point!
Awhile ago I remember someone making a post, either here or at doctoreleven about the Beast Below. They talked about how the rhyme, while it alluded to the star whale and Starship UK's secret, was a bit vague and random. They also mentioned how it could be part of the arc. In past seasons, the arc was always much more subtle, but in this past season (forgive my vocabulary, I'm American) the arc has been very present, and it wouldn't be surprising to have something that apparent (I really can't wait to rewatch the season in its entirety this summer and notice all the hints). In the post, this person discussed how the 'beast below' could be referring to another Doctor. They then went onto say that it may be the 'jacket Doctor' from the Time of Angels, if I follow the theory it was indeed another Doctor and not just a continuity error. However, building on this theory of other Doctors and beasts below, I think the other Doctor could likely be the dream lord, especially after we see his reflection in the TARDIS console as the Doctor flies away.
Sorry I lack a conclusion. Bye!