We could change PySpark's installation procedure to use a setup.py script that downloads the dependencies and bundles their .pyc files into a .zip that acts as the Python-equivalent of an assembly JAR.  This would make it easier to depend on third-party Python libraries without having to bundle them.  We're also trying to [remove binary artifacts from the build](https://spark-project.atlassian.net/browse/SPARK-1002), so that rules including .eggs.