You can take a look at the eth2.0 specification here https://github.com/ethereum/eth2.0-specs https://github.com/ethereum/eth2.0-specs. They have solved the not

You can take a look at the eth2.0 specification here https://github.com/ethereum/eth2.0-specs https://github.com/ethereum/eth2.0-specs. They have solved the nothing at stake problem, and they currently have 8 independent client implementations written in different languages that can 'talk' to each other on a multi-client testnet. They are much further along then people may realize.