Me too. It would be super to have ability to build project supporting information in picture form, and tie them to OmniFocus actions/projects. There are products out there that do something similar - several mindmap products have the concept of mindmaps for projects, plus mapping links to nested actions etc. Not an easy thing to do well, I'm sure, and whereas they do mindmaps well they do tasks not-so-well.

I find OmniGraffle's layouts to be not quite right for mindmaps, though they are good for so many other things. It does pretty well in managing the outline, however, and this is especially useful when you get your head around the 'Diagram Styles' feature.