Google dropped a double whammy yesterday. First it announced the final preview of Android M, signaling the closeness of the consumer launch of the next Android version. And to emphasize that point, Google also formally christened that next version and gave it formal numbers. Android M, which is API 23 for developers, is major version 6.0. But it will forever be known by its more popular nickname: Android Marshmallow. So what has changed in this latest and last preview? They're not as ground breaking as the last, but they are still significant nonetheless.