According to a recent report from AndroidPolice, Googleis currently working on redesigning the stock Android icons for its apps Gmail, Calendar, Youtube, Maps, the Play Store, Hangouts and Google Plus. The new style is referred to as “moonshine” and will give them a much flatter look, somewhat similar to how the web apps icons look, which have a much flatter design compared to the current Android icons.
All though this is currently just a rumor it does seem like something likely to happen as the icons will look much more familiar for those who are used to using Google’s web apps and making it easier for people to transition from one platform to the other one. The image bellow from AndroidPolice shows how the icons could look, it is yet unsure if these will be the final form.