In a special evening event, Scott Chacon from GitHub gives an excellent overview of Git for developers, with a lively back and forth from the audience.
Yehuda Katz, member of the Rails core team, describes the many new ways to extend Rails 3, including the overall philosophy of extending ActionController and how to use ActiveModel to better integrate your non-ActiveRecord Ruby objects and Rails.
Tammer Saleh of thoughtbot demonstrates Hoptoad, their Rails exception notification service. By aggregating repeat error notifications Hoptoad stops the email onslaught from a production bug while still providing appropriate notification and escalation.
Ezra Zygmuntowicz of Engine Yard demonstrates Solo, their new cloud offering for the deployment and management of lightweight Rails, Merb, or Rack apps.