The network effect in Second Life is not as durable as that famous effect that so nurtured AT&T.   Second Life is made up of many networks. It is lumpy.  Communities form strong networks.  But the communities are not all strongly connected.  Some pieces could break off and run their own world. 

This article continues previous articles about the implications of OnLive for the future of Second LIfe.
Future of SL is beyond e-tech. Now on to s-tech
Future of SL Beyond e-tech (continued)
VR in the Cloud

This article contnues previous discussions about OnLive and the implications for VR grids :

• Future of SL is beyond e-tech. Now on to s-tech
• Future of SL Beyond e-tech (continued)
• VR in the Cloud

Start with two more concepts:  Hypergrid and Mixagrid

Hypergrid

From the Wiki: "The hypergrid is an extension to opensim that allows you to link your opensim to other opensims on the internet, and that supports seamless agent transfers among those opensims. It can be used both in standalone mode and in grid mode. The hypergrid is effectively supporting the emergence of a Web of virtual worlds. "