Just saw a demo here:
http://www.screencast.com/users/tfennelly/folders/Camtasia/media/4b184ca6-9a6d-4817-b15d-aac8576d36bb

It would be nice to be able to reorder fields on either side of the graph when you are doing the Java Mapping. In other words it would be nice to not have to have lines cross if at all possible. It would be even better if this would be automatic that fields in an object would order the same way in both views.

It would also be nice that dragging a field into a mapping would prompt for a dialogue box to ask/see if all the other like mappings should be applied rather then having to apply them.

Quickstarts around the smooks editor that are easily importable into JBDS w/o any messing around with anything.