The Symfony blog has been posted spotlights in several of the improvements in the 2.7 release of the framework over on their blog. Each of them describes the changes and includes some sample code showing the new feature in action:

• Serializer component
• Twig profiler
• Security improvements
• the new Asset component
• Productivity improvements
• Choice form type refactorization
• Dependency Injection Improvements
• Form and Validator Updates
• VarDumper improvements
• PHPUnit Bridge

Keep an eye on the Symfony blog for more of these component spotlights and improvements as they're released.