> Most of programming will be done socially [...] via
> small changes [...] from hundreds of people
This seems a little extreme. I'd venture that right now 'most of programming' is private code, or small side projects/toy code (i.e. single-developer projects).
I'd think that the total SLOC in side/single-developer projects is miniscule compared to the total SLOC in social projects (e.g. Linux, GCC, Emacs, etc.), and even smaller compared to the SLOC in private/corporate code-bases.