Does Rust have a way to make a program pluggable. In C the plugins I create are .so files that I load with dlopen. Does Rust provide a native way of doing the same thing?
Yes. There's a module std::unstable::dynamic_lib that enables dynamic loading of libraries. It's undocumented, though, as it's a highly experimental API (everything in std::unstable is undocumented). As @dbaupp suggests, the source is the best documentation (current version is af9368452).