The problem is Google is putting tons of resources into improving Google Maps... for Android. They have no motive to do so for iOS, in fact they have motive to not innovate on Apple's behalf.
One of they very few advantages of android over iOS is mapping. This looks like the first step in exploring other options, or a stall while they get their in house solution ready.
The same is true of Mountain Lion offering native Vimeo support over YouTube.
I would be shocked if there wasn't a new native map app in iOS 6. For what it's worth I think Google maps would still be available in the App store. In fact that might force Google to update it.
It has been known for a long time that Google has nothing to do with the Maps and Youtube apps on iOS, they just provide the data. It's Apple that makes the apps.