Why would Gmail/Gtalk take a performance hit, as it did for me today (almost unusable), when Google owns the world's largest data centers?
Maybe you can't centralize the Web? (rhetorical question)
In other news, the IETF is finally tackling the p2p traffic problem after BitTorrent (more specifically, their uTorrent client) started using Reliable UDP instead of TCP (not sure if they've open sourced this reliable UDP implementation) for file transfer not just for DHT and NAT hole punching.
I had written a post on the Internet's successor, the Worldwide [Wireless] Mesh
, which mentions P2P traffic problems in context of 802.11s and forthcoming standards. Maybe what the IETF is doing now re: p2p traffic would be also inclusive of wireless mesh standards (to support P2P better over wireless mesh)