Google Maps is already "flat" in the sense that it doesn't use gradients or shadows. (The exception would be the controls in the corner which have a shadow, but that still exists in this example). The only thing someone did was switch up the color scheme and remove all the text, i.e. everything that actually makes a map useful. I fail to see the point of this. Could someone explain?
The other thing that is different is that the subtle borders around city blocks and things like that are gone. Those borders help increase contrast, making things easier to distinguish.
