Right... notary is about authentication
It would be really useful to have this process done online so that it can avoid a trip to a notary public office (and pay the $10 or so fee).
The problem is not easy to solve.. but a central agency (a e-notary service) could potentially use a remote system like webcam or voice to verify you. It needs to be robust that someone can't easily impersonate. [likely use a live-person on the other end and may be use your biometrics like iris-scan to confirm it's you]
I see still for some financial transactions.. while 99% of work can be finished online (read: without leaving your home), a last bit still needs a notary.. if this task can be done online, it will be nice as you can instantly finish up some financial transactions (e.g you do an asset transfer to another person online with your finanical institute)