Since it's framed as 'in between' Rust and Go, is it trying to target an intersection of both languages' use-cases?

I don't think you'd want to write an operating system in Rue. I may not include an "unsafe" concept, and will probably require a runtime. So that's some areas where Rust will make more sense.

As for Go... I dunno. Go has a strong vision around concurrency, and I just don't have one yet. We'll see.