Soon! So soon! Also, there's a neat project called node-trello that uses the API, and one of their example scripts backs up all of the boards for an org: https://github.com/lmatteis/node-trello/blob/master/example_...
Re:How Trello is different
by bobbygrace on Friday January 06, 2012 @04:19PM
(#3435081)
Data export is at the top of the 'In Progress' list of the Trello Development board: https://trello.com/card/board/data-export/4d5ea62fd76aa11360...
Now that the API is 'done', it shouldn't be long until this is up and running. More about data, privacy, etc. here: trello.com/privacy
What if they decide to shut down some day? You lose everything. Unlikely? yes. Possible? Also yes.
Offer a backup function, and I'm yours.