It is interesting that when I considered next language to write a side-project in, I was choosing between Ceylon and Kotlin.
In the end I did choose Kotlin. My reasons included:
* support in IDEA
* focus on java interoperability
* nice interop with android
but the main thing probably was, that I trust JetBrains that they will support Kotlin in the long term, while I don't think RedHat has any projects depending on the language.
So, why would you choose Ceylon?