My initial reaction is "fucking gross", but that's only because Google Maps has taught me what map colors should be. I'm old enought to have used a book-based atlas even before Yahoo Maps was popular, but young enough I don't remember what that coloring was.
While I do find it harder to understand what is going on with the map, esp while driving, I'd be interested in reading more into why they made the change. So fucking help me God if this is just some graphic artists idea of what looks better...