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 4m 16s ago
View selected tracks, PDFs in QuickLook windows
downloaded 10m 47s ago
Copy chosen tag info from one set of tracks to a different set of tracks
downloaded 18m 37s ago
Perform search-and-replace on text in your choice of tags
downloaded 24m 11s ago
Exports and then re-imports selected tracks' artwork
downloaded 29m 22s ago
Capitalize the first letter of each word in selected track names
downloaded 45m 57s ago
Copy the file of the selected track using its Start and Stop times