I have been an admirer of IntelliJ IDEA, but used mostly Eclipse and Netbeans. Google announced the early access preview of Android Studio around Google I/O, and it is evolving quickly. I have to say I am blown away by how good it is. It is based on the Community Edition of IntelliJ IDEA, an open source project.
I have found it extremely easy to migrate from Eclipse ADT to Android Studio. I’ll not repeat what is already well documented at Migrating from Eclipse. The interface designer is nice and stable. Developers used to Visual Studio and Xcode have one less reason to fret Android development.