Certainly, as njn has brought online each new memory profiling feature, he's discovered something ridiculous we were doing in Servo (e.g., copying things we thought we weren't; continuous memory leaks; poor use of underlying native gfx buffers, etc.). I suspect that in the near term there's plenty of low-hanging "Servo is doing something dumb" fruit to keep us busy while we log some Rust implementation issues for the smaller things.