A release candidate for what will become WordPress 2.9 has become available on WordPress.org.
WordPress 2.9 will feature a significant number of changes to the popular blog / cms platform. You can see a full list of features and enhancements on the WordPress 2.9 page.
The development team is in need of people to test out plugin compatibility.
You can grab a copy of it here: http://wordpress.org/wordpress-2.9-RC1.zip
Screenshot of the new Admin Interface: