Heck, everything will become decentralized, even nation states will become obsolete ...
Not before our culture makes violence obsolete by beginning to govern the world with reason instead.
At the rate we're going, that could take
quite a while.
Taking the history of human kind into consideration , lets say 100.000 years, reason is (maybe arguably) the winning meme (
http://en.wikipedia.org/wiki/Meme) and once it reaches a certain point, there's accelerated or exponential growth in adoption. Quite a while is a relative notion.