Definitely we'd like to, over time! This is just the start, and contributions are welcome :) Servo's a big enough project that we try to reuse C and C++ wherever possible, while being open to eventual Rust rewrites of those components. We're pragmatic above all else.
Also note that, for patent-encumbered codecs, to meet the goals of being freely distributable we unfortunately have to use the platform's native C and C++ implementations, so we're stuck (until the patents expire).
This was created primarily for Servo to use, and in general we don't have enough resources to Rust-ify all the things right now. Eventually, maybe, but not now.
