This posted link could be another piece of the jigsaw (Solidity, IPFS, IPNS, ...) that I think will come together to make interesting apps in the future. Solidity doesn't mean necessarily spending $100 to make a function call - there are other chains, off chain stuff being developed, and you could host a private chain for your app.

While none of this stuff can do something new you can't do with Postgres - you can create more open and perhaps 'honest' applications where everyone can see the data-engine and understand it. So it is more of a cultural shift. For example, if you make a Twitter this way, you don't need to rely on an API. The data is there for everyone, all of it.

For example, take Uniswap. It's not a company like Facebook, it's an open protocol. Swapping tokens is now functionally open source because of that. There is no "Facebook of swapping tokens". And this can be used as a building block for other apps. Not necessarily just "gambling" or "trading" either.