I found some things listed here (there are 174 NPR podcasts, who knew?) that are not in the iTunes directory which is good. It is also missing some things, from APM, for instance, which is bad. The other thing, the major thing, it has no “show all” functionality, shame on you NPR web designers, I say shame on you.
http://www.npr.org/rss/podcast/podcast_directory.php

In comparison, Public Radio Fan lists 250 podcasts. Eh, maybe the new thing is not so great.