Thank you for your comment! At some point I would definitely like to add excerpts from the text, comments on significant propositions in the maps, and maybe even summaries of each chapter.
I think that some (but very few) people who read the map will be caused to go read Principia. More people, I think, who work through the map will have a better impression of the text's value and view it as being less mysterious - and more fun - than they thought.