In nine months, Rust has gone from version 0.1 (its first public release) to version 0.4 (expected next week). Much of the work in that time has involved removing (!!!) features from the language and polishing what's left. Version 1.0 is anticipated in the first half of next year.

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).