It's lap 10 as I write this, and Button's just pulled off a beautiful tactical decision. Too bad he went off on turn one (yeah, mimicking commentators here, but hey).
Also, this race has already been more exciting then Bahrain. The no refueling (as I guessed) is actually helping here. Drivers are pitting purely on the basis of their tyres instead of wasting laps on bad tyres because it's not time to refuel yet.