Have built a demo app with Ethereum in November. The tooling was ok, but not amazing.
IMO one of the main problems is that you need trusted inputs for most "interesting" or "valuable" computations.
IMO one of the main problems is that you need trusted inputs for most "interesting" or "valuable" computations.
There's a lot of talk about replacing Uber/AirBnB/Facebook/etc with decentralized applications but I believe those things are still at least a few years away. Complex applications like those are going to require significant base infrastructure that just doesn't exist yet.
The "Trusted" inputs problem is complex and I don't believe there will be a single solution. Some applications will be fine using trusted oracles. Others will need a more trustless model which is going to require on-chain reputation systems which in-turn is going to require some level of identity/anti-sybil system.
At least a few years? LOL. I would give it 20 years.