No doubt the concept is just awesome but I do have some suggestions :
1] The converted pdf should also capture and highlighted text or line or mouse trials (created with addons like Line Marker or Firegesture)
2] You should be able to see a preview of what is going be the outcome after conversion and if possible which can then be edited so that only what is needed can be converted rather than the whole page.
I think other than this rest everything is up to the mark. Keep up the good work guys. Cheers