Myspace opens up, just like facebook. A few differences though, only devs for the first month, no proprietary markup language, open social support, and caja javascript scrubbing support. Close to being too late.
Open Social APIs published, with very simple demos. Looks really interesting.
Social Networking is slowing down, shown at Creative Capital. What's really fascinating is the Dec 2006 to Dec 2007 numbers. Facebook hasn't doubled users in a year, and they are spending only 15 extra minutes on fb.
Amazon offers facebook AMI and tutorial - these guys really have it right. Next thing, they'll offer prioritized EC2 location so it's right next to the fb server and they'll have "distance/time to fb" rates :-)
OAuth published the 1.0 spec. Very interesting, and exactly what I want for a lot of integrations.