The first version of Workflow was just released and I'd be interested to hear what you think about it. Workflows are one of those pieces of infrastructure that are useful for many types of business software, which is why I was surprised that something like this didn't already exist. It may be an illuminating example of community goals when you compare this to the Java community which has a gaggle of open-source workflow implementations. (Lots of standards, too...)

The distribution comes with decent documentation, a good amount of tests (not comprehensive but far more than a set of 'use_ok()' statements), and a sample application so you can start poking and prodding very quickly.

M-x auto-bs-mode