Akamai bought Red Swoosh last week. I think it was about time that CDNs realized that the best way to fight your enemy is to join him, and that is exactly what Akamai has done here. CDNs were struggling to compete with P2P content distribution since P2P was, well basically free. This is a good move for Akamai, at least as a defensive strategy to control the P2P space and prevent other P2P players from eating into their business.
From a technical point of view, it also makes a lot of sense. P2P systems cannot provide the sort of service level guarantees that content producers demand (e.g. movie studios). Peer upload capacity is quite limited, and fluctuates greatly depending on the number of peers, etc. CDNs can instead provide assured capacity since their servers sit in well-provisioned data centers, kicking in to assure a certain SLA when P2P fails to do so. Not just that. Using CDNs also helps ISPs better manage their networks since less upstream traffic is generated. Traffic flows from the center of the network to the network edges, fitting well with current ISPs traffic engineering models which assumes that most traffic is downstream.
Overall, to me CDN and P2P is a marriage made in heaven. The next battle will be which P2P system becomes a standard (bittorrent, red swoosh, …) ? What about an HTTP-based P2P system and we all stop re-inventing the wheel?