It hasn't really been a secret that Microsoft was going to change http://home.live.com to be more of a social network. There were more than just the two articles I reference below 

Sweeping Changes At Live.com: It’s A Social Network!

 http://windowslive.com/ComingSoon?ocid=EML_PROED_HM_Acq_WL_getbetter_112008

Now that I have had a chance to see it for myself and to be invited to some of my friend's networks I am not really sure how I feel about it. I like the look and feel but when I started digging into the settings for my profile I saw that the default was that everyone could see my network. I understand that social networks are built on sharing and for that reason I don't know that I have a problem with the default but it would have been nice to have been told that.

Another issue is that a lot of the invitations to join a network are coming with just the first name of the person. I understand this is also a setting in the profile but it is a little annoying to have to go and look to see which John or Andrew is inviting me to their network. I did find that if I go into my profile I can see the invitations and there it had the full name of the people who had invited me.

I already maintain contacts on Plaxo, LinkedIn, and Facebook besides my e-mail contacts so I am not sure how many other web sites I want to use for social networking but I will give live.com a try if for no other reason than I am always checking my hotmail accounts and it isn't that much more work to add in people to my network.