Has anybody heard if they've finalized a spec yet, or at least come close? I've thought about getting into Rust from time to time, but the lack of a finalized spec and/or stable reference implementation has always scared me off.
If you'd like to try out the language, I recommend working off git master rather than 0.3; the language has been dramatically simplified in Rust 0.4.
The upcoming 0.4 release (any day now) makes a big push to get a lot of the syntax pieces in place, but still has many rough edges. Beyond that the standard library is still an incomplete and inconsistent stew of different styles.
Rust is still firmly alpha software, but should stabilize significantly in the next year.
And it's not like it's been ten years yet.
What's shipping with it?
I have a bit of the same impression that the other poster has, that it's always in development without something stable. I hope that gets dispelled sooner or later, because, for better or worse, fuzzy marketing type things like that matter.
From a pure marketing perspective, sure, maybe it would be better to finish more of the design and implementation before talking about it publicly. But Mozilla's pretty committed to working in the open, and that has its own benefits. For example, significant parts of the Rust implementation were created by contributors who were not paid Mozilla staff, including a Google employee (in her spare time).
(Disclosure: I'm a Mozilla employee but not part of the Rust team; I've contributed a little bit to the Rust compiler in my free time.)
If you really feel the need to compare with Go, measure the time from Go's first public release (2009) to its first production release (2012).
(By contrast, Perl 6 has been in development for over a decade, with a half-dozen implementations in various stages of completion.)
[1] https://github.com/mozilla/rust/wiki/Note-development-roadma...
At these Go meetups, companies are presenting what they're using Go for in production already, with great success. Go is not difficult to program in, Go is functional, Go is performant, Go is developer friendly.
That is not to say that Go doesn't have warts, it does (32-bit garbage collecting anyone? or the slow regular expression engine?), but people from Ruby, people from Python, and people from JavaScript are gravitating toward Go and _enjoying_ it.
Go also has excellent stewardship in the form of Pike et al.
In my mind, at least, the gap between Rust and Go is pretty big at this point. This is why Rust feels like vaporware (especially compared to Go).
People like to compare Go and Rust, and I think the comparison is pretty natural. The difference is that Go already has "boots on the ground."
If Rust releases something awesome in the next few months, the gap between Go and Rust could rapidly close (depending on developer adoption). But, in my mind, the longer Rust takes to iron out the quirks of it's syntax (not implementation, syntax!), the wider that gap will get.
It's the same gap it's always been -- a few years.