Issues with Facebook Connect
I have always been bewildered by the way Facebook implemented Facebook Connect. It is an awesome idea in theory, and could potentially become the de facto standard login system for the web, but it has developed a terrible reputation for giving connected apps the ability to post to your Timeline and spam your friends. It has happened to me so many times that I don't even bother connecting to apps anymore unless I trust them 100%.
His proposed solution would make me use Facebook Connect ~infinitely more.