I just did another update to the iPodder.org Educational Category, adding a handful of new feeds, and more importantly, adding a new "English as a Second/Foreign Language" category.
The new ESL/EFL category is being edited by Robert Diem (thanks, Robert!), which will definitely help keep the updates fresh.
This last round of updates hasn't shown up on the iPodder.org directory yet, but they will be there the next time Adam's OPML crawlers update their data (in a few hours?)
If anyone wants to take on the K-12 or Higher Ed. categories, please let me know. If not, that's cool, too...