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.
Applet assists with swapping, copying, appending data between track tags
Enter text for the selected tracks' Category tag
Copy Artist to Album Artist of selected tracks
Export artwork of selected tracks to parent or specified folder
Convert selected tracks and export the converted files to a new folder
Capitalize the first letter of each word in selected track names