Be careful. One expensive case maker says no because of the dual flash. Better be darn sure that the case will allow one to take pictures without being a bit blocked by the case itself.
Apple's official statement on this is in the
FAQ section of this page:
http://store.apple.com/us/buy-iphone/iphone5s
"Do cases made for iPhone 5 also work with iPhone 5s?
While iPhone 5 and iPhone 5s have the same shape and size, the camera and LED flash are different. So cases made for iPhone 5 may affect the camera operation of iPhone 5s and vice versa. When shopping for cases, you should choose one made specifically for the iPhone model you own."