The relationship between WordPress and Tumblr has always been pretty friendly: Tumblr's own blog used to be on WP, WordPress.com supports Tumblr as a Publicize option alongside Twitter and Facebook, our Akismet team sends them daily emails of splogs on the service, and there's healthy import and export traffic both ways.
Matt MullenwegPeople might start with LiveJournal or Blogger, but if they get serious, they'll graduate to WordPress. We try to cater to the more powerful users.
Matt MullenwegI don't care how someone lives or how good their spoken English is. I do all of my interviews on Skype text chat - all that matters is their work.
Matt MullenwegWordPress, it's a complex tool; it's like the back of a digital SLR... but that doesn't work on a phone.
Matt Mullenweg