The Migrate module provides services for migrating data from various sources (other CMS frameworks, external web services, or other Drupal installations) into the local Drupal environment. It has been used to migrate sites such as The Economist, Examiner.com, Stanford Law School, and PayPal and eBay's developer forums (x.com) to Drupal.
Migrate 2.6 is now in beta. Today I will cover some of the most significant changes at the framework level, for those who have been developing their data migrations using Migrate 2.5 and earlier. There have also been significant UI changes, and the introduction of a framework for implementing wizard-style UIs for defining migrations, which will be covered in future posts.