I'm impressed by the rate at which Rust has begun accumulating serious ports of and bindings to valuable libraries.
There's already varying levels of support [1] for a number of serialization and compression formats, databases and computation frameworks.
Obviously there's still a long ways to go before Rust can be considered a 'batteries included' programming experience, but it's exciting to see how fast the community has put this together.
[1]https://github.com/mozilla/rust/wiki/Note-wanted-libraries