Rust: it provides extremely strong guarantees about your code at compile time so that usually it feels like a script language with C/C++-levels of performance. And the best part: no data races, and no runtime garbage collector overhead.
Which is another reason to be excited about Rust - it is to the best of my knowledge the only new language that allows you to write an entire programme or part of a programme that does no runtime memory allocation. While GC in most languages is not problematic in most cases, this makes it suited for embedded or hard-realtime work where C/C++ may have been the only option up until now. But it still has all these expressive, high-level features and safety mechanisms that makes it so suitable for programming well-structured, trustable software. There's a learning curve moving from GC to the ownership system, and maybe a plug-in garbage collector makes sense in some cases, but then the system does support that.
And then there's the tooling. Setting up a cross-compiler (again, embedded work), bringing in libraries from online repositories, packing up code modules for distribution and reuse, all that, is as easy as you'd expect coming from the web world because of the excellent Cargo system.
In short, while it might not be completely battle-tested yet, I think it has a better shot at being the "one language" that scales from tiny throw-away projects to large, complicated ones, and from watches to super computers than anything else I've seen.
Another consequence is the sheer range of applications for which this language can be practically used: systems and concurrent programming obviously, but also Web, realtime, embedded and even supercomputer programming. The reason for that is that rust mostly feels like a light weight scripting language like python, but because of its performance characteristics can viably be used as a drop-in replacement for C.