From what I saw in the latest presentation by Martin, we can expect Scala 3 to be released in late Spring/early Summer 2021.
Part of the release testing is building the community release[0], which is a large part of the relevant Scala F/OSS code out there.
Whether you consider that to be production ready you have to decide for yourself, I myself am pretty happy about it.
Keep in mind that for now Scala 2 style code will still be compiled and you can use existing Scala 2 code in your Scala 3 project. The migration should be pretty smooth.
[0] https://github.com/scala/community-build