I think Apple already dropped the ball with Apple Maps. Most people have either switched and aren't coming back, or don't need or use Maps enough to have an issue with the current version.
Where do you get your data? 20M have downloaded the app, but there are over 100M iOS 6 users. I have both and use whichever suits the situation (Which essentially means if I have an address I use Apple maps.)
Google Maps is great for searching, but still won't have Siri integration (And doesn't even have their own voice search...) and doesn't have address book integration. It will probably get those in time, but by then Apple will have had more time to improve their data with integration from other services like Foursquare.