Social networks have an intrinsic problem of fragmentation. If half of your friends are on myspace and the other half on Facebook, then your convenience is greatly diminished. If someone’s Github profile is empty, they may still be submitting patches in Bitbucket.
Open source has been around since long-before Facebook. The technologies of development collaboration still bear timeworn scars from its long, diverse, and fragmented history. We still depend on libraries maintained in the Cathedral style and operating through mailing lists. Even the Linux kernal doesn’t host its primary on Github, which gives a certain air of irony to this article.
I don’t see git or Github going away or even losing their position at the top. On the whole, I’m sure their collective importance will continue to grow, for a while at least. But this isn’t the end-all-be-all. Trust is always hard to commodify.