I have started a mock JMS implementation. Basically the idea is that individual components of the mock JMS server can be independently configured, used etc, etc with an XML based configuration that gets loaded prior to each test. Objects such as JmsMockProviderAdapter, JmsMockServerSession etc, etc. will stand in for real JMS objects and allow for ease of testing the Inflow stuff.
The idea is that this should be able to run outside of JBoss. I looked at the MockRunner stuff for JMS, but it didn't seem to be quite what I needed.
Current working (rough draft) implementation can be found in