> Given that, calling it a "risk" is, I think, a bit of an unfair characterization. A "source of occasional discomfort", would be fairer.

What I meant by "risk" wasn't technical difficulties, but a contingency plan if the young language doesn't take off. Even though Kotlin and Ceylon are very similar, it's easier to change back to Java from Kotlin than it is from Ceylon (and I'd argue that it's easier to gradually introduce Kotlin into a project -- a class here and a class there -- than Ceylon).

Still, both Ceylon and Kotlin are a nice, gradual evolution of "blue-collar" programming languages, and I hope one or both gain widespread adoption.