I think basically everything necessary to use the Steem blockchain for Q/A usage like Quora and StackOverflow/StackExchange is already there, except we lack a tag to specifically find and answer these questions. Now when I am in the train, I think a good start would be to think of such a tag and add it as a chainbb forum. If that works out fine, maybe we can build a better interface around it over time.
I think it would be a great way to use Steemit to not just help people out monetarily, but way beyond with stuff that just someone else on the network would know the answer to. And we can already do this, just by thinking of a tag sanctioned for this it will be way easier to find each other's questions. If we combine this with good tagging for kinds of questions, I think this can be big, and also improve fair payouts and the value of contributions/knowledge on the Steem network.