I've started on a simple implementation here:
https://github.com/repole/snakemq-pubsub
By no means production ready, I'm not sure if that even functions yet, but by the time anyone else sees this message hopefully I've added some tests and polished things up a bit. If anyone is interested, feel free to provide feedback or contribute.
A sincere thank you to you, David, for developing snakeMQ. It's been a huge help to me, really nice to be able to bundle a message queue in a Python app without having to worry about compiling or installation.