FrozenImporter. Docs forthcoming. I plan on all finders and loaders (and most likely hooks) to live in imoprtlib.machinery. Utility stuff will end up in importlib.util. Higher-level API stuff will stay on imoprtlib directly (e.g. import_module).
planned for the package. There are no docs yet, but they are coming once the API for the first new function, importlib.import_module() is finalized.