Lucas Gonze:

"I've been thinking of it like viscosity."

Robert Welbourn:

"P2P for communication is doing just fine: look at Skype and the emerging efforts in the IETF to define a P2P version of SIP."

Adam Fisk:

"These systems are never labeled as p2p precisely because they work so well."

Johannes Ernst (whose blog is a daily read):

"Decentralized systems are much harder to design... to debug... to deploy... to maintain"

Brian Behlendorf:

"Decentralized systems are also much, much harder to 'monetize', to exploit the crowd of users to the unique advantage of one company"

Mike Dierken responding to Lucas Gonze:

"REST definitely is about decentralized control - multiple organizations interacting without arduous up-front coordination. It's an enabling technology for organizational decentralization, as opposed to protocol or messaging decentralization."

Clay Shirky:

"I got beat up a few years ago for suggesting that Napster was a better architecture than Gnutella on every axis except legal risk. ... But I'm a Behlendorfian on the question of overall utility -- the general case of 'aggregate cycles/storage' has been commodified by Moore's Law-style economics so quickly that supply outstripped demand long ago. Most of the decentralization is going on inside the corporate world, as with GFS or grids, as opposed to involving end users directly."

Julian Bond:

"Because the bulk of the system [Skype's] is decentralised it's very hard for them to offer centralised web services. Which in turn makes it hard to offer the sort of web client embedding that GTalk (and now AIM) can do. ... There is a pattern here though for a mixed architecture. Mostly decentralised with reporting up to a centralised stats and web services server. And ideally where anyone can run one of these servers or build one on top of a well documented API. Move as much as possible of the peer to peer comms out to the edge, but still aggregate some of the system in the centre."

Gary Lawrence Murphy:

"Unfortunately most of the very large ISPs took to denying their subscribers the right to run servers"

Sergue Osokine:

"Of course there are no use cases - how would we know what these use cases are going to be, if all development attempts are sued into the ground long before they approach anything resembling a really interesting scale of the search scope - the global one? Could you tell much about the future Web use cases in 1990?"

Adam Fisk:

"This is less the decline of p2p and more a dramatic lowering of the barriers to entry to starting companies using LAMP."