That's a great question, I'd like to believe Steem can do free/instant accounts, but I know others may disagree. It's a big hinderance for Steem that it requires payment for the creation of an account.
Flipping to RaiBlocks, I know I've read about people wanting to fork XRB for smart contracts, but it's all rumors and speculation at this point. It's likely possible to do with the block lattice structure, but who knows when we'll see it :)
Each account being a chain itself kinda complies with my long-term hold requirement of having atomic ownership (like with the case of https://pillarproject.io/) so it's pretty exciting stuff!