Sharapova's Service Motion?

Watching the match right now with Sharapova playing against K. I've noticed that her service motion is different than before. If you watch closely, she doesn't turn her right serving arm in a circular motion before impact of the ball at the top of her toss. She now simply raises it up and hits the serve, which I think is ineffective to create power from the serve. Probably something she does to prevent aggravation to her shoulder? Regardless, that's probably going to be the difference maker in a lot of her match outcomes IMO...

She looks good, apart from a few crappy double faults here and there, but I'm just wondering, does she look good because her competition is so weak?

I'd like to see Maria play a top player, obviously at the French to see where she really is.