Scaling is of primary importance, even more important than Proof of Stake, Buterin said. PoS is important, we need to stop wasting electricity like right now, so it’s important, but if no scaling, the only use is token speculation. So I really believe we need scalability so that people can use blockchain applications, he added. The Ethereum Foundation (EF) is more focused on research, Buterin said. It’s not like Apple where we launch a ready product. We’re not trying to outcompete or monopolize. We believe in decentralization, we want different implementations, different teams. EF is continuing to expand, continuing to take on new devs. There’s a grants program, so if you want to implement Plasma, sharding, or a smart contracts language to compete with Solidity and Vyper, you can apply for a grant.

https://www.trustnodes.com/2018/03/06/casper-pretty-close-sharding-number-one-priority-says-vitalik-buterin