Orality, literacy and computers

I am reading with interest Mark Goodacre's blog on orality http://ntgateway.com/weblog/. It leads me to wonder what, in the distant future, will remain of this ongoing debate? Where do blogs, email and the internet fit into the oral/literary matrix? Is there a possibility that there will be no transcribed evidence to witness that this debate, or indeed any other, has taken place?
If everything becomes digitised, as some would suggest, and we become a truly paperless society what is the literary legacy of our society to the future? Will our back-up disks survive and be readable? Or will the late 20th/early21st century be perceived as the new dark age?
Just wondering.