There's a picture on the JBoss site for the ESB that shows the ESB supporting Microsoft Excel. How does the ESB accomplish this? I have looked in the documentation and forum and can't find any information.
I think that diagram is an "in theory" type thing. There's nothing in the ESB that helps you do this right now, but you could write an action that uses JXL to process the Excel stream. Someone is working on adding this to Smooks too, so it will eventually be supported via that channel also.