[javajosh]

The biggest real-world benefit of Kotlin is nullity prevention and immutables (of which Optional is a corollary).

It's not clear whether Loom will be a big hit. Personally, I think the Actor model is the best application level concurrency "primitive", and Loom is just about fibers & continuations, both of which are parts of Actors but aren't really Actors themselves.

[native_samples]

No, but if your threads are basically 'free' then you can just model an actor as a thread+LinkedBlockingQueue or whatever channel abstraction you want to use.