Indeed they do, but IMHO not as intermediaries.
We need an entirely new financial architecture based upon "Peer to peer" market networks operating within (inherently mutual) partnership-based frameworks.
I wrote this
http://www.exchange-handbook.co.uk/index.cfm?section=articles&action=detail&id=38754some 8 years ago, in the aftermath of a "Dot Com" I set up, and it is now being picked up by one or two IT gurus.
And this was recently published by the Carnegie Institute
http://www.policyinnovations.org/ideas/innovations/data/000085