WordPress 2.9, also named Carmen, was announced on the WordPress development blog in their post, WordPress 2.9, oh so fine for anyone to download. Of couse, those who can automatically upgrade, you should be able to see the notice in your WordPress administration panel and be able to upgrade from there.

Some of the great features introduce were:
- Ability to mass upgrade plugins
- Post/ File Restoration for accidental deletions
- Built-in image editor
- Easier ability to embed videos
- Upgrading TinyMCE and SinglePie
- Support for canonical URLs
- Ability to register post thumbnails
- Improvement of PressThis
- Theme Editor Improvements
- Hooks and Filter improvements

In fact, there were quite a few mentioned at the development blog. Of course, this makes 1 step closer to merging WordPress and WordPressMU, which were hinted about earlier this year.

Related posts:

1. WordPress 2.9.1 Fixes A Few Issues
2. Canonicalization in Your WordPress Blog