Bill Johnston shares research about Social Media ecosystems on the Online Community Report at:
http://www.onlinecommunityreport.com/archives/537-Social-Media-Ecosystem...

Here's the post:

Sandra Charan has an interesting view of the social networking wars in OpenZine at:
http://www.openzine.com/aspx/Zine.aspx?IssueID=1662h

Here's the post:

The War of the Social Networking Giants
Sandra Charan
3/18/2009

The Social Networking giants are at war. The big players MySpace and Facebook still rule the roost, in terms of influence and network traffic but a new player Twitter has entered the scene, and though it has a long way to go to be a real contender is gaining followers fast.