Obligatory warning: This script has been designated as an obsoleted "Retro Script". There is no guarantee that it will function as described with modern versions of iTunes and/or macOS. If used in its current form it may not work at all without modification and, at worst, it may corrupt or destroy data.
iTunes will stop updating a podcast if you have not listened to at least one of its episodes in five days. This script will batch-update every podcast subscription so you don't have to manually update each one individually.
I have posted instructions on how to create a launchd agent to run this script automatically and invisibly in the background to ensure that your Podcasts are always updated.
Possible iTunes bug (July 17, 2014): Looks like the iTunes AppleScript command updatePodcast command is broken as of iTunes 11.
downloaded 53s ago
Exports and then re-imports selected tracks' artwork
downloaded 7m 55s ago
Set the Plays of selected tracks.
downloaded 25m 35s ago
Displays files in iTunes Media folder not in iTunes track library
downloaded 26m 32s ago
Finds and displays any empty folders in the iTunes Media folder
downloaded 32m 1s ago
Move selected playlists to a new or existing folder
downloaded 32m 50s ago
Perform tasks on a batch of playlists; rename, delete, duplicate, merge, more