The dev.enworld.org simply needs to be changed to www.enworld.org to get the feed to work. I bet that it's a preference that can be changed in the software to get the source to generate correctly.
The one feed that would be great to have would be a feed for the news on the front page. Anything that it posted there shows up as being under the /articles subdirectory. I can't seem to figure out if there is a feed just for those posts. The main feed listed on the main page seems to be a compilation of all posts from all forums. I think a better place for that feed would be on the main forums page.