Following last week's .zed format reverse-engineered specification, Loïc Dachary contributed a POC extractor!
It's available at http://www.dachary.org/loic/zed/, it can list non-encrypted metadata without password, and extract files with password (or .pem file).
Leveraging on python-olefile and pycrypto, only 500 lines of code (test cases excluded) are enough to implement it