- Much more lightweight and faster than Groovy
- Statically typed
- Offers about the same level of expressivity as Groovy (closures, etc...)
- Much, much faster than Groovy
The only downside is that it's still in beta, but already working great and, obviously, with awesome IDEA support.
Perhaps that should be "most Groovy people are excited for Kotlin". The reason "Groovers" look at Kotlin before Ceylon could be because Groovy creator James Strachan and Groovy++ creator Alex Tkachman jumped over to Kotlin.
I prefer the most conservative, slightly incremental Kotlin myself, but it's purely personal and certainly not a knock on Ceylon, which was implemented by people I have a lot of respect for.