In fact, for the time being, I'd still recommend new development use bcrypt or scrypt (and not PBKDF2 for the simple fact that typical APIs around it aren't spe

In fact, for the time being, I'd still recommend new development use bcrypt or scrypt (and not PBKDF2 for the simple fact that typical APIs around it aren't specifically tailored to password hashing, don't handle salts transparently, etc.). Argon2 winning is great, and it's almost certainly an improvement over existing methods, but it's also still relatively new and should be approached with typical caution.