The Beta channel has been updated to 28.0.1500.44 for Windows, Mac, and Chrome Frame, and 28.0.1500.45 for Linux. Full details about what changes are in this build are available in the SVN revision log.
For more information about features coming to Chrome, check out the Chrome Blog.
Interested in switching release channels? Find out how. If you find a new issue, please let us know by filing a bug.