In 10 years to have a game like Sword Art Online is utterly impossible.
For any machine to run the game it would be necessary to have the processing power of a really powerful quantum computer.
And, well, The guy above me already said, more or less, how a quantum computer should work, even though I believe they're doing it wrong.
In either way, to create a quantum computer with our current technology, it would be needed a facilty by the size of the LHC. And there aren't many people that can have one of those at home.
Considering that the scientists have yet to figure out how to make a quantum computer work, and that this will take at least 20 years (remembering that each day we learn something different about these particles, making it even harder) there are still vary many years until these things can actually be taken to people's homes. And yet, these computers will be GINOURMOUS (aftar all, we are talking about particles traveling at the speed of light).
Sword Art Online is pure fantasy. HOWEVER!
In 2 years there will be enough hardware technology to create games like The World (dot.Hack series), and if it goes well, in 15 or so years there can be virtual reality games like The World available for us to play at our houses.
But this tech, as far as I know, is as dangerous as the technology described in both series... So... God knows. =P