I don’t often write posts that are this short ;-). But having read the NY Times article + discussions here and here on Google and Yahoo’s plans for e-mail and it’s possibile ability to become a social networking thing I can only say:
Dear Yahoo, Microsoft and Google e-mail, Forget Facebook, start innovating e-mail!
Finally!
@vanelsas 
Nice fore-thinking, Alexander. I guess we’ll see how this evolves, but, to me it is one of those things that seem so natural that I can’t help but think “how didn’t they figure it out before”.
@Esteban thanks. It beats me as well why they haven’t done this before. There are now a few alternatives available, but as Yahoo, Google, and Microsoft hasve the largest user bases, they should be able to innovate and keep their users to them. We will have to wait and see.