You can ignore the Blockchain hype for identity solutions, it is superb marketing; but suboptimal technology. You can also ignore biometrics for a spell. Instead, the real breakthroughs, especially in authentication, will be based on elegant math and crypto, e.g., Zero-Knowledge Proofs (ZKP). These have the added benefit of being privacy-preserving, and amenable to user control of identity attributes. ZKP has been identified as a category for many other solutions in the future, not just identity. Conceived at MIT in 1985 by Shafi Goldwasser, ZKP is still young. You will see it in many other contexts as appreciation and recognition evolves.