It was a bit The End of the World meets Dawn of the Dead meets body-swap schtick, I thought. And I'm beginning to wonder if Davies is one of the Doctor/Rose shippers in disguise, because the first ten minutes or so it's just the Doctor and Rose acting like they've just had ten hours of sex since leaving Earth.
I should stop focussing on the bits I didn't like and think about the bits I did like, I suppose. :)