Enterprise Messaging with JMS
This use case does not really offer anything above and beyond the use case for C++ messaging or the one for .NET messaging. C++ dominated the programming world for a at least a decade and .NET dominates at least the Windows desktop. Enterprises are not getting rid of solutions they spent man-centuries or millennia developing and that raises the question of how they should be talking to each other. When you combine those two giants with Java and JMS, you can end up with a unified messaging approach across most or all of your enterprise.
Being able to standardize on one messaging infrastructure can yield economies of scale and sizeable cost savings, particularly when you can use a free JMS provider and an inexpensive, fast, and reliable cross-language integration solution like JMS Courier.