Don't read this if you haven't been watching the latest Who.
Kathleen pointed out a theory -- or related pair of theories -- which would explain River Song and make her an interesting and much more palatable character for me. They're very simple:
River Song is a Timelord. The front-running candidate is Romanadvoratralundar, Romana, companion of Tom Baker's Doctor for a couple of seasons. The second candidate is The Rani, the mad scientist of Gallifrey.
Of the two, Romana fits extremely well. The interchange between River and The Doctor in the Tardis -- down to River apparently knowing more about the Tardis than the Doctor (or, alternatively, insisting on changing operations of the Tardis that the Doctor, crotchety old man that he is, has gotten used to) -- the other arguments and quips, and just the general behavior (to the point that they appeared to be, as Amy observed, married) fits PRECISELY with the way Romana used to behave. She would puncture the Doctor's self-superior behavior, but then when the chips were down relied on him to solve the problems because, in the end, that was what the Doctor did best.
The Rani would also work, though not so well because River Song has shown many human traits that simply didn't belong to the Rani. For her to have those, she'd have changed a lot.
Either one would explain the oddities of her background (including the interchanges about when they've met; she's not implying she hasn't met him yet, just that HE hasn't quite twigged to who SHE is, and she's waiting for him to get a clue).
This still wouldn't fix the problems of the Suddenly Munchkinized Angels, but it'd make River Song no longer a problem for me.