Drupal 8 is scheduled for release in late 2014. It will bring improvements like configuration management, REST services, responsive design, improved multilingual support, and more core modules. While most contributed modules have not yet been upgraded for Drupal 8, upgrading from Drupal 7 is not necessary due to feature parity and potential issues. It is best to upgrade when doing a major site restructure or if using Drupal 6. The migration process involves moving configuration, functionality and content using the Migration module. Upgrading during a restructure has advantages over upgrading after by allowing integrated testing and adaptation to the new structure.