Another social network by Microsoft? It may look like a research under Microsoft Research Fuse Labs according to the official blog. There were already previous social networking sites by Microsoft but they don’t seem to be having so much momentum whatsoever.
Feature-wise, it contains wall posts, interests, people/me and parties. Interests are probably the tags of interests in your profile that people can search for you based on the interests like trying to add you into Socl. The People feature may seem to be like Friends on Facebook or perhaps mistaken for being like People Metro App and Parties feature, well, whatever it is, it is the video related feature that allows you to watch videos with others in Socl and chat together as you watch.