Google is making another run at Social Networking and using Gmail to do it this time. After their previous attempts this is probably their final shot at getting some traction with social networking, if they miss here, they should just forget about it. At first glance it appears that they acknowledge Twitter and Flickr but they are not going to help anyone lean towards Facebook.
Google Wave did not get it done, Orkut, Zingku, or how about Dodgeball?
As usual they are diving in with API support at Google Code.
I will not pass judgement until I have some real time to invest in Google Buzz, but looking over the API, it looks like they realize the importance of connectivity to other systems and keeping the system as open as possible.