About the trust and reputation issue, I think blockchain technologies could play an important role for decentralized services like this.

I would like to see a multipurpose reputation / trust system based on the blockchain, exposing all the needed features as a simple library and / or HTTP API, ready to be implemented by apps and websites.

I think we are still in a period where a lot of products are built either in a centralized way, or all on the blockchain and decentralized technologies (like IPFS). It makes sense as we are still in the experimentation phase, but it could change in the near future. People could start using the blockchain where it is the most efficient today, as a brick part of a product (e.g. to build a solid decentralized reputation system), instead of being the foundation layer of the product.