They've been promising this for years. I've been working in the blockchain space for 2 years and I have experience working on scalable distributed systems as well so I'm skeptical of Ethereum's approach to sharding.

Aside from major technical challenges that are specific to Ethereum, a major problem with sharding a blockchain in general is that it somewhat obscures the reality that each shard is in fact a separate blockchain with separate network participants and so it might as well have a separate unit of value and not be constrained to a single token.

The ideal solution IMO (to really promote decentralization) is to have multiple independent blockchains and networks interlinked together via open source decentralized exchanges - This will mean that any token's value could be instantly determined relative to that of any other token in a trustless way by polling decentralized exchanges.