The new .blog domain is administered by Automattic, the people who created and run wordpress.com. Even so, it's cool that it can be used with sites created with any blogging software. This is truly in the spirit of the web, open source, and the Internet itself. (Democracy and capitalism too.)
Users should be free at all times to choose what's best for them. And developers should be able to combine the output of sites, to create new flows. And the input of a content system should seamlessly flow to any other content system.
Today in 2016, the web is unfinished. It should always be so. There are more connections still to be enabled or created. Meanwhile many of the biggest tech companies try to trap users in "silos," without free movement, with no ability for developers to build on their work. Ultimately this leads to stagnation, and eventually explosive discontinuous change.
Tech has a choice: change can come with steady innovation or all at once.
I'm glad to say that my friend Matt Mullenweg and Automattic are consistent champions of user and developer freedom. That's why they host .blog for all to use.
They could have said "blog" == "wordpress" -- many companies would have -- but they didn't. That's very good! I wish more big tech companies had that philosophy.
Every developer who embraces this idea is courageous and futuristic. No one should want to win because users can't move.