I had shown a proof of concept of this idea at EclipseCon, albeit in a very simplified manner by coupling an emitter to a TreeView component in SWT. But this guy took it a step further and has taken it a step further and has an emitter that outputs directly to an SWT table. This opens the door for all sorts of cool opportunities, such as customized action handlers for interacting directly with SWT components.
Not sure why I didn't think of passing in the composite as a render option as I went about it in a different way, but this is definitely cool stuff. With a little modification to handle groups, you can do all sorts of cool interactive report interfaces using RCP or RAP :)