Well, given that LJ no longer wants to let me comment, and a larger mass of people than before are proclaiming their willingness to ditch Facebook ...
I dunno. I mean, my thoughts about the balancing act a given social network would need to perform to be affordable and accessible to all (or at least as wide a swath of people as possible), have an easy-to-learn intuitive interface, allow you to export your data in usable form and take it elsewhere, let you know exactly who has access to your data at all levels, let you follow people's posts wherever they are, allow for nuanced privacy levels that are somehow still easy to manage (in posting; in actual profile display; in searchability), gets us off this train where anybody but actual network community members are the customers (advertisers, investors, etc) and you are the product - my thoughts boil down to ZOMG HRAD. (Geek Feminism has a decent list of the basics: http://geekfeminism.org/2012/01/16/re-post-social-networking-requirements/ .)
And even if you create a social network that addresses all of these issues, you still have the problem of enticing people to move to the more open platform. How many of you who had LJs moved to Dreamwidth at any point in the last five years? Did your friends move with you? Did you find yourself performing an annoying balancing act between the two? What about Diaspora? (What about Diaspora?) Do you miss the days when you could just toss your friends' feeds in your RSS reader, because standards meant you could?
Heck, I'm not even sure how I'm supposed to find my existing friends on Ello. Post on Facebook and hope my entry makes it through the algorithm obstacle course?