The “Restrict Categories” plugin has been added.   Administrators can now add users to their blogs and restrict which categories that user can post to.

http://wordpress.org/extend/plugins/restrict-categories/

The WordPress software has been updated to the latest version, 3.3.  Please see the WordPress site for the new features and bug fixes in the latest version here:  http://wordpress.org/news/2011/12/sonny/