Not OP but from the perspective of the industrial side: no track record, no formal standard, changes too fast, incomplete documentation, doesn't have an extensive commercial and supporting ecosystem (e.g. Parasoft, Java Path Finder), limited pool of experienced programmers with embedded and regulated environment experience. Arguably, it falls under the heading of "too new".

I'd prefer to deal with known knowns rather than the known unknowns or gasp unknown unknowns of something new. It's a very conservative position, but it's borne out of the expense associated with mistakes and corrections of.

I don't care quite as much about the lack of a proven track-record -- I understand the value there, but I love tinkering and trust Rust enough to not have any concerns about core stability (maybe a mistake, but there it is). It's mostly the lack of a stable HTTP library / ecosystem that throws me off; it seems like everything there is changing pretty frequently. That's just my impression though, and I'd love to be wrong :) I mentioned in another thread as well that the last time I played around with Rust, it seemed like most of the useful Cargo packages were dependent on the nightly version, which definitely gave me pause. I can't seem to find any of these packages now, though, so that's either changed or was an incorrect impression.