The new Google Maps app has a simplified interface that focuses on the map. It has a lot of things in common with the new Google Maps for desktop, including the missing features. For now, there's no support for My Maps (it will be added later), many layers are missing, Labs features are no longer available. Map caching is now a hidden feature: type "OK maps" in the search box and the app will preload the map you're currently viewing. Google Latitude has been discontinued and replaced by a Google+ feature. In my limited testing, the app was pretty slow and laggy, so Google still has some work to do to optimize the app.
On the plus side, you get a Google Maps interface optimized for tablets, incident reports, dynamic rerouting and some integration with Zagat and Google Offers. "You can now see reports of problems on the road that you can tap to see incident details. While on the road, Google Maps will also alert you if a better route becomes available and reroute you to your destination faster."
There's also a new version of Google Maps for iOS that will be available soon and will add support for iPad.