Google Maps blew everyone the day it came out.
Google Maps was the iPhone of Mapping, and continues to be so. And, much the same way others are pretty good (Bing Maps isn't bad) - they are all still compared to Google Maps.
Apple Maps is the Zune? No, that's not a good comparison, the Zune was a competent technical product. The Kin? Maybe not that bad. Apple maps is the Kindle Fire (original) of Mapping. Starts off kind of crappy, but might turn into something better with a lot of work. People will still want an iPad though.
I'm pretty sure I switched the day it debuted.
The day google maps came out was basically the last day I used mapquest.