I think mapping software really has two major components.

1) Updated POI - People just use their mapping software because it puts things into a location aware content.
2) Turn-by-turn or good navigation interface - people wanting to know how to get from point A to point B.

Currently Google Maps is the leader for updated POI (at least for US). There is no current application (that I am aware of) that can provide the second piece of functionality.

I'm perfectly fine with having two different apps for those different pieces of functionality.