I recently saw it article in infoq:
https://www.infoq.com/news/2016/09/ceylon-13-android-support
I installed the plugin in Android studio 2.2 without problems. But when In the Android view, Right-click on app > Configure Ceylon in this Module
I got it:
Error:Class com.android.build.gradle.internal.scope.VariantScopeImpl does not implement the requested interface com.android.build.gradle.internal.scope.BaseScope
I think (and hope) that if you update the Ceylon IDE plugin to the very latest version which was released two days ago, then this bug will be gone.
Here's the release notes.