This talk by Fred Wilson is a great overview of some of the big 'disruptive' technology forces. And the couple of minutes I've linked to above is a smart explanation of the shift from heirachies to networks.
I'd quibble with one element of it.
He says "we are seeing technology-driven networks replace bureaucratic heirachies". I'd suggest that what we'll actually see are people-driven networks replacing bureaucratic heirachies - with networked technologies making that possible.