Android Studio is a new Android development environment based on IntelliJ IDEA. It provides new features and improvements over Eclipse ADT and will be the official Android IDE once it's ready. On top of the capabilities you expect from IntelliJ, Android Studio offers:
Flexible Gradle-based build system.
Build variants and multiple APK generation.
Expanded template support for Google Services and various device types.
Rich layout editor with support for theme editing.
Lint tools to catch performance, usability, version compatibility, and other problems.
ProGuard and app-signing capabilities.
Built-in support for Google Cloud Platform, making it easy to integrate Google Cloud Messaging and App Engine.