wordpress_migrate supports migrating WordPress blog exports (WXR format) into Drupal using the Migrate module. Import of posts, pages, comments, attachments, tags and categories is supported. Imports can be rolled back completely.
The current stable release of wordpress_migrate is 2.2. If you are using an earlier version, you should upgrade to 2.2 as soon as possible - in certain circumstances (specifically, if your WordPress file has multiple authors with the same email address), rolling back a WordPress import can delete pre-existing Drupal users and all their content.
The main theme for version 2.3 will be #1826134: Support new Migrate wizard framework - this will involve a complete redesign of the UI, changing it to a step-by-step wizard process and enabling more flexibility (e.g., separate options like attachment fields for blog posts and pages). While this work is going on, the -dev release will be less stable than usual, and if you want to experiment with the new UI it will be important for you to keep your wordpress_migrate and migrate modules up-to-date with the latest -dev releases of both modules.
Original wordpress_migrate development was sponsored by Acquia.