Kevin, this is not an answer, but an open (and too short IMO!) discussion that Evan raised some time ago, that you may find interesting: pump.io as next generation blogging

I suppose the blogosphere is more intended to setup an unequal conversation (few post, many read and comment), and pump.io (and the other social networks) allow more equal-to-equal conversations (we all post, read and coment). But this is just my opinion.

I'm not a tumblr user, so I cannot say a word on that. My equivalence table would be:

• Twitter is like GNUSocial but worse

• G+/Facebook is like Pump.io/Diaspora but worse

• Youtube/Flickr is like MediaGoblin but worse

• Medium is like Wordpress but worse

For (automatic) publishing other sources in pump.io, in addition to pumpbridge, there is Spigot for publishing an RSS feed in pump, and brdcst.it (you'd need to setup your instance, macno's one does not work now). They all are in the Clients wiki page.