They replaced it with some sort of (visually beautiful) crap that serves no useful purpose. Not only is it inferior to Google maps in functionality, but it's worse than just using your gps, like seriously it sucks!
The new maps app is not complete garbage, but it cant find simple locations, fails at finding out where you are, doesn't have the compass type walking thing Google maps does, and worst of all, does not have transit options.
Did I mention it barely understand the concept of anchor and direction. So be warned: Don't get ios 6 until this is addressed!
Apple Maps Sucks