Adobe Photoshop Lightroom 3.4 Release Candidate is now available. Aside from bug fixes, there are new cameras and lens correction profiles.
If you already have Lightroom 3, this will overwrite your existing version, which you would have to reinstall. Eventually the final version of Lightroom 3.4 will be available as a free update to Lightroom 3 users.
Note: This version expires 5/31/11. If you don't have Lightroom, this is a way to get an extended trial.