It works. tricky part is making it work with our blogging tools.
Try this: go to iTunes, Advanced, subscribe to podcast. Give this URL
http://www.uvm.edu/~waw/index.xml
That is a static XML file, created with a text editor. It contains an enclosure:
iTunes recognizes the URL, and presents a username/password box. Pretty slick.
Trouble is, the scripts that generate RSS feeds with enclosures for both Movable Type and WordPress attempt to access the URL via HTTP while generating the enclosure statement (to determine the length and type). Neither can, because the scripts don’t have any credentials. WordPress does nothing; MT gets really screwed up (Article doesn’t post, rebuilding indices fails).
I can probably engineer a WordPress fix, not sure what to do about MT other than hard-code the URL in the RSS2 template (or maybe there is some template tags magic. worth a look)