I got Google Maps Android API v2 to work perfectly on my Android Application by downloading the library, adding it to workspace, then referencing it as a library.
Bu
You should not worry about those Dalvik warnings. I believe those shows up since the Google Maps library is compiled to an API level that is higher than the one running on your phone. Some classes that are available on the higher API are not available on your phone but the library must have some code to compensate for that already.