The problem of web identity isn't caused by passwords, it's addressed by passwords. Eliminating passwords only obfuscates the problem!
Remember that cutting the Gordian knot was a bad thing. It symbolized a regression to brute force and violence. The knot puzzle represented intellectualism over barbarism. By cutting the knot with a sword, Alexander the Great propounded brute force as the solution, when in reality that was the problem.
The brute force approach of addressing Web Identity by re-engineering browsers/html/protocols to natively support automatic password handling is a fool's errand at this stage in the development of the Internet.
Thankfully what's great about the Internet is that it solves its own problems through a bottom up natural selection process based on pure useage.
Much like every other web usability paradigm that came before it, proper and effective third party login credentialing will become second nature to the web development platform and ultimately a norm of internet usability.
Until an ubiquitous hardware solution changes the game, users will always need to remember (or use tools to remember) the passwords to their major account providers, but eventually any website and/or service that requires identity to function properly will not have to annoy the user by requiring their own identity forms/procedures.