As we all know, a typical password validator formula is a great way to encourage people to choose "Secr3t!", or something else equally bad.

I'd really like to see a password field that auto-generated pass phrases using full english words from a sufficiently large wordset (in the vein of "correct horse battery staple"), possibly even enforcing such phrases as the only valid type of password. Every user gets a strong password they can actually remember. (...although possibly a non-starter for mobile contexts.)