I would personally like to see something which used the power of the blockchain to encourage more real and direct action on climate issues. Whether this could be a part of the marketplace or not, it could be a powerful way to move things on from our current stalemate. There are two things that people mainly seek in life, security and respect. Steemit is unlikely to provide complete security (as in financial), but it could definitely serve as a platform to offer respect and validation. Real, tangible ideas for helping humanity are so much more valuable than monetary rewards in the long run. I know you can't eat respect, but it can definitely help your emotional, and psychological well-being when times are tough.

One of the great ideas from Cory Doctorow was the concept of 'wuffie', which was a form of reputation currency which was earned for deeds and actions. As he later said it would make a terrible currency, but maybe allied with the blockchain it could actually prove very powerful?