Apparently, paying for coffee with an iPhone was a big success. Starbucks has expanded their test to all 1,002 outlets inside Target stores. The company is taking it one step at a time and currently has no plans to further expand it to the 11,000 Starbucks stores in the US -- yet.
You will have to update your app to version 1.2.1 to take advantage of the expanded roll out, but if you have a Starbucks Card Mobile app, you've most likely already done that.
So, the next time you find yourself at a Target, you'll have to find a way of justifying your purchase of a cup coffee that costs more than the shirt you just bought.