I have been using the beta version of Lightroom 2.1 for the last month or so with great success. Well, now Lightroom 2.1 is ready for release! You can get the downloads for Windows here and for Macintosh here.
The readme file can be Downloaded here. A few things to note are below.
Formats Not Supported
Formats that are not supported with this update are CMYK Files, Photoshop files WITHOUT the Maximize Compatibility setting (no composite image), REALLY large image files and video files (get video editing software if this one is a problem).
New Feature Highlights
Some memory leaks and folder synching issues have been resolved. The downloadable fix for upgrading keywords in a LR 1.4 Catalog to a LR 2.1 Catalog is included in this release. Some Photoshop integration issues were fixed.
All in all not a huge update, but several important Metadata fixes are included. The beta for Lightroom 2.1 has been stable for me, so I would recommend upgrading when you can.