Taken from an early postach.io blog - http://blog.postach.io/tumblr-import-twitter-posting-ui-updates-speed-increases

You can import from Tumblr!

Any text, image, etc. that was previously "published" on Tumblr will come over to Evernote as "published" and your drafts will stay drafts. Simply click "Edit", then go to "Import & Sharing" and choose the "Connect Tumblr" button.