I absolutely can't see Kingston as a regular or as the Doctor's partner. I thought she was so unbearably smug in the first of the two parter, and had no redeeming features in the second episode. I really do feel that Moffat has severe inabilities when it comes to writing plausible, exciting and appealing female characters for scifi ('Girl in the Fireplace' is another perfect example). Which is odd, given that I liked his characterisations in 'Coupling'. I know a few other people who feel the same way as me about Kingston/River Song, but we seem to be in the minority! :)