That site fails terribly at supporting OpenID: it only supports four authentication providers, and doesn't allow a user to enter an arbitrary OpenID URL.
"Properly implemented", OpenID looks like http://ikiwiki.info/ikiwiki.cgi?page=index&do=edit : a choice of common OpenID providers to help users who don't understand OpenID, an option to use an arbitrary OpenID, and an option to use a username and password.
Properly implemented, BrowserID looks like one big shiny "sign in" button, and yet it still supports any service the user wants to use, and better yet no third-party service at all. Seems like a big improvement to me.