Things are much much much improved from before. Of particular note is how much cleaner the Oauth2 API's are.
OmniAuth recently reached version 1.0 and has a number of nice additions. In this episode we’ll take a look at a new strategy called OmniAuth Identity which allows users to create an account by supplying a user name and password instead of logging in through an external provider.
Watch and read the awesome tutorial at railscasts.com