I've been using Go for a few hobby projects, and I like it so far. It's considered beta, and parts of it has changed once or twice since I started using it late last year, but it's stable enough for hobby projects.

I haven't had any issues myself, but they don't recommend using it for production systems yet.

I believe goroutines are the "killer feature", they beat alternatives like Java threads and multiple Ruby processes hands down. Among the languages I know, Go and Erlang are the primary contenders for the "most convenient multithreading" prize.

Go aims to have the "simplicity of a dynamic language with the performance of a static language", I'd say they are reasonably close to that goal.

For my purposes, Go doesn't replace Ruby/Python for shell scripts and quick prototyping, but it is a much nicer alternative to Java and C for performance.