Sort of offtopic, but.. since Manish has already clarified the intent below... I am just curious - would you have drawn a similar conclusion from the headline if the language in question was not Rust, but a more popular/stable one, like say JavaScript/C? "Shipping C in Firefox"? (asking purely from a linguistic point of view)
Err, I didn't mean to say that Rust is unstable in the literal sense. Apologies! Just meant to highlight its "newness" in the given context (i.e., relative to other languages) :)