BrowserID (https://browserid.org/) does exactly that. Once implemented in a browser, it effectively turns authentication into a key exchange with the browser.
As far as I can see, it's not different from all the other solutions. When you logged in to Hacker News you had to notice that there are tons of already working alternatives out there. It's also one factor authentication and requires password. So why not to use OpenID, Google, Facebook? Because it's linked to browser, it's most probably possible to steal your identity. So it's not prefect solution either.
