With this commit, you can if you want. This code decouples Rails from external queue solutions. If your application needs to interact with a queue, you only have to write it once and you can use a standard API to do it. If your external queue solution (your DB queue code) conforms to the API, you can switch it out with another conforming solution when your needs call for it.

As someone pointed out in the OP comments, this is like Rack for queues.