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 12m 57s ago
Copy Artist to Album Artist of selected tracks
downloaded 31m 46s ago
Exports and then re-imports selected tracks' artwork
downloaded 31m 58s ago
Gather audio tracks whose files contain no artwork metadata
downloaded 51m 47s ago
Apply selected CD's CD Text to its disc and track tags
downloaded 52m 1s ago
Use tag info from selected track to search Amazon Books for cover art
downloaded 54m 3s ago
Move selected playlists to a new or existing folder