Social-Networking Sites Open Up

The availability of APIs is absolutely the way to go, perhaps inducing a symbiotic growth relationship between multiple web networks/services.

A new, niche network could integrate, say, Facebook, into their service. This would help the user accept the new network, as he wouldn't need to again add to his already detached web identity.

This extension -- or compliment -- of networks is a potential solution to the problem of fragmented identities spread across the web.