Working for an Arabian bank I had to find a very fast way to connect two applications. In this context I tried Mule (http://mule.codehaus.org). Mule is an open source bus tool with the support for a large number of protocols. It's very simple to understand and use. In less than a week the application was ready for tests.
If customer wants to use different or alternative ways to connect their, just add inbound entry point in the configured bus. Dot. Mule supports natively: JMS, SOAP, EJB, TCP/IP Socket, RMI, etc. You can write a custom transport component (called Provider) and plugit.
All transformations will be reused. Transport now is a very small detail ;-)
Unfortunately MULE doesn't provide a CORBA transport, so we moved outbound CORBA calls at Transformers level. The clearest solution was to write a CORBA provider (using OpenORB implementation for example), but time was very short.
In conclusion I'm sure to use Mule in future applications, since transport and transformation concept are very common and with Mule the life is easier ;-)