What is the outcome of new social network tools?

I am quite impressed about the success of Facebook. The intimacy aspect, the clear design and usability combined with all sorts of applications are probably some of the success factors. However, I wonder what is the aftermath of this social network, and how many different results come out of it? I ponder how many people really get something out of it, beyond adding friends and exchanging statuses. Actually, I started recently experimenting myself with statuses because I believe in network effect, and I am anxious to see the results. So, for example, if I posted a question in Twitter--which appears as a status in Facebook--I could potentially reach an audience, and that might help me - as Johannes Schunter and Jürgen Eichholz pointed in their idea for social network platform in an organization. By the way, Joitske Hulsebosch wrote a nice post about our experiment and you can follow my Twitter attempts here (I will write about this Twitter thing in another post).

In contrast to blogging or writing collaboratively in a Wiki, one can say that Facebook, per se, has little to offer. Take a look at Facebook groups. They are basically just forums with photos, which lack much needed social network features such a widgets, RSS, profiles, etc. to get more information from people, about a certain topic and many other incentives for interaction. I started the Web2fordev group myself and I am a member of some other groups as well. What are the benefits or the outcome of these groups? There are surely exceptions such as the Burmese campaign group, which was helpful for coordination and triggered a lot of attention. In a simple mailing list such as the Dgroup, one achieves so far a better exchange. I guess we still have to experiment more to find the right tools for networking. Obviously, the desire for exchange is there but when will we have the best tools to apply it?