It still amazes me that Apple's authentication is based on a single login name (email address) and password. I will never switch my email away from Google to any provider that doesn't provide the same 2 step authentication awesomeness that they do.
(For the uninformed, you tie your Google account to your mobile number. When you log in using a valid username and password, it sends a text message to your phone with an authentication code. That way, a hacker also needs access to your mobile phone to get into your account.)
This is really irrelevant to this topic though - they are discussing third party use of Mac OS X Server.