With more and more things going digital scanning in documents instead of filing them is more and more common.
The biggest problem is where most decent scanners come with OCR and create searchable PDFs this is a huge problem in Ubuntu.
The closest Ubuntu comes is making bad OCR text files that are barely readable.
With search-able PDFs Ubuntu's Beagle tools can easily be used to track down invoice numbers and specific products on receipts.
I would think this type of project would get high priority.