There are many discussions on SO about database abstraction. I'm a bit surprised there aren't similar discussions about message queue abstraction. Rather than designing to a specific MQ implementation (RabbitMQ, IBM MQ Series, IronMQ etc.), we would prefer to use a neutral / abstracting layer, so the underlying implementation could be changed without major surgery later.
Can you recommend a solution?
The most promising option so far appears to be Kombu which is described as a high-level abstraction of the AMQ protocol (e.g. RabbitMQ) but supports several messaging back-ends that don't require AMQP, including REDIS, Beanstalk, Amazon SQS, CouchDB, MongoDB and Zookeeper -- in varying degrees.
I will give this a try and report back. Kind of don't like answering and accepting my own question :) -- will look at other answers to and change the accepted one if yours is better.