I was under the impression Rust was being developed by Mozilla to eventually be their language of choice for implementing software like Firefox precisely because C/C++ leads to too many (security) bugs among other things. At least one of the reasons, anyway..
A: Mozilla intends to use Rust as a platform for prototyping experimental browser architectures. Specifically, the hope is to develop a browser that is more amenable to parallelization than existing ones, while also being less prone to common C++ coding errors. The name of that project is Servo.
Q: Are you going to use this to suddenly rewrite the browser and change everything? Is the Mozilla Corporation trying to force the community to use a new language?
A: No. This is a research project. The point is to explore ideas. There is no plan to incorporate any Rust-based technology into Firefox.
I was being careful and said software _like_ Firefox :) From discussions I had with people about Rust it seemed obvious that if it reached maturity then it could be considered for new projects starting from scratch.