In the past (iOS5 and earlier) clicking on a link for directions within a website opened the separate maps app and provided directions. How do I force links in websites, that would normally open a google maps link in a "desktop" web browser, to open the new external google maps app? I do not find the current google maps website adequate (can't figure out how it would provide dynamic (voice) directions) and the new apple maps app is not opened by those links.
As Matthieu Riegler said, when you go to the Google maps site you will be prompted to launch the app. Unfortunately, there is no way to do this automatically.