After Google announced Android support fon Kotlin, I started having a look at it and played around a little bit.
By now there's one result: Kotlin is beautiful, it works like a charm!

To start doing something productive with it, I migrated the small codebase of this blog to Kotlin.
Boilerplate code was reduced A LOT - basically there's nothing left.
Spring and Wicket dependency injection works without any modifications.

Having a look at Kotlin is definitely worth it!