Author of that comment here, let me update it with some new links for you. :)
Putting Rust into production at Dropbox: https://www.reddit.com/r/rust/comments/3wrgl0/what_are_you_f...
Some preliminary feedback on using Rust at Dropbox: https://www.reddit.com/r/programming/comments/3w8dgn/announc...
edit: Once you google for dropbox rust, you find some really interesting stuff; here's an overview
https://news.ycombinator.com/item?id=9724849