I'm not aware of the latest news from Valhalla fro...

# language-proposals

[dmitry.petrov]

I'm not aware of the latest news from Valhalla front (Andrey Breslav knows more). We actually have some internal prototype for Scala-like value classes (single field, can be considered "newtype" equivalents).
But there's more in Valhalla that actually affects Kotlin design: