The Google Reader team just added the ability to rename folders and tags in their popular newsreader. Unlike before, folders and tags can now be renamed easily through the Google Reader settings page, or through the context menu in your subscription list. In addition to folder and tag renaming, Google Reader has also phased out support for older browsers, and disabled offline access for Gears, which should come as no surprise to anyone.
Folder and tag renaming [The Official Google Reader Blog]