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 28m 40s ago
Gather audio tracks whose files contain no artwork metadata
downloaded 45m 29s ago
Detects if a track's file's metadata contain image information
downloaded 46m 19s ago
Set the Plays of selected tracks.
downloaded 47m 39s ago
Applet compels you to rate unrated current track
downloaded 48m 53s ago
Delete characters from the beginning or ending of selected tracks' name, artist, album, comments, composer, or show tags
downloaded 49m 6s ago
Copy chosen tag info from one set of tracks to a different set of tracks