If you have looked at Google's recent design ideologies, first announced at Google I/O 2014, you will see them revolve around skeuomorphism in its most basic sense. By that, I do not mean that they want to make it look like a folder, a metal slab, or a radio button. Their concept is that objects should look like physical objects which behave with physical accuracy, even though they are just simulations of light.
Image Credit: Android Police (and their source)
Basically, rather than having a panel with a toolbar, buttons, and columns, have a background with a page on it. Interface elements which are affected by that panel are on it, while more global actions are off of it. According to Android Police, who make clear that they do not have leaked builds and readers should not believe anything until/unless it ships, the Google Play Store will be redesigned with this consistent, albeit broad, design metric.
Basically, if you are navigation bar, pack your desk and get out.
If true, when will these land? Anyone's guess. One speculation is that it will be timed with the release of Android "L" in Autumn. Their expectation, however, is that it will be one of many updates Google will make across their products in a rolling pattern. Either way, I think it looks good… albeit similar to many modern websites.