I have not really been blown away by much of Sia's writing with/for the pop gals, but I have always said that I would love to hear Britney sing a really somber song like "Breath Me". Could be her next Everytime!
I won't be ready if Britney delivers a Breathe Me...that's one of my favorite songs ever. But it's very likely we could get a song like Diamonds, which I wouldn't mind at all. Excited to hear this though