interesting - not sure if it's really needed though - I've used Redis and Resque before and found it's performance was blisteringly fast. (Resque was made by Github https://github.com/blog/542-introducing-resque)
* Forcing a dependency on a particular queue
* Writing a wrapper for all possible queues
* Falling back to queue-less behavior in the absence of a detected queue
They just use the Rails queue and it works on whatever real-world queue the user picks. Definitely good infrastructure IMO.