In theory this is a fantastic idea. WWF formats are basically PDFs that cannot be printed.
However in practice, I’d still prefer the option of being able to print my documents (PDF) but choosing not to print them, unless it cannot be helped.
The reason for this is because I scan a lot of documents on a regular basis and get rid of its paper equivalent, but if someone desperately needs to see a paper copy or to have it faxed to them, I need to be able to print it.
You’d be surprised how many places insist on a paper copy or a faxed copy (like the government).
I always ask if I can scan and email it to them, but it only works part of the time.