There was a debate on the media show a while ago with Alan Rusbridger and some guy from the Times talking about the paywall, and Rusbridger said it was unlikely the Guardian would replace its current presses, so predicted that sometime in the next 10 or so years the Grauniad will only be available on line.. Will it be the first though? Dunno. Personally I think print has still got legs, too many people are averse to screens.. me included.. if I could only read a newspaper on a screen, I would stop reading it.. and there are plenty of people who work in, say, factories and building sites who read a paper every day who do not have access to a computer.. can't think of many labourers who would want to take an ipad to work..
As with print, the major problem for going virtual will have to be subsidy from either advertising, sponsorship or ownership. And it's probably from last catergory that an online paper will arrive. One of the google/facebook corporations will say the world needs a new unbiased source for news and information and give it a punt off the back of their existing operations. But again how they will bear the costs, structure and pay for proper journalism seems a problem that will not go away in any future of news dissemination.