e6747d8 decouples eager loading from class caching.
2801786e moves from config.preload_frameworks to config.eager_load_namespaces, allowing you to register any Ruby namespace from your application for the eager loading process.
As of 73c02220, ActiveRecord::SessionStore has been extracted from Rails into a separate gem.
The update_attribute saga continues. 50bdb924 reverts the commit that removed it, so as of right now it's back in Rails 4.0.