I'm really really starting to like the idea that River Song is Romana.
Sadly, there is a flaw in this theory. If she is Romana, she knew him during his fourth incarnation; so she's definitely seen him younger than incarnation ten (which she has already denied).
Otherwise, though, it would make so much sense! It would explain why she knows so much. His name. High Gallifreyan. How to fly the TARDIS. The snark.
Of course, it would be better if her name were Frederika.
Moffat has said the truth will come out in series six... so now I'm eager for that, even though I haven't even finished series five. I'm also not enamored of Eleven. He's had some great lines and scripts, but he hasn't grabbed me yet. Part of me keeps wishing it was still Ten. *sigh*
I also keep wishing for Rose, though, so...
And Amy Pond is a fantastic companion. All the best bits of Rose, Martha, and Donna rolled into one. Even though I do feel sorry for Rory at this point... he's like Mickey Mark II.