Not yet using Android Studio? Now is a great time to start using it for Android apps development. You can check this video introducing Android Studio.
Android Studio is the official Android IDE. You can download it at http://developer.android.com/sdk/index.html. To those migrating from Eclipse, you can check these pages: Migration Guide and Tips and Tricks.
There is also a new Google+ community for Android Studio discussions at https://plus.google.com/communities/103491657963571270604.