Traci: As promised, we [FeedBurner dudes and dudettes] are pleased to announce the immediate availability of iTunes metadata for your podcast. [cut] After a[n] audio post has been created, it must be properly transformed into an RSS2.0 feed with enclosures in order for it to be distributed correctly. That's where we come in. FeedBurner ensures that your feed is not only configured correctly, but also incorporates the appropriate metadata for inclusion in a variety of podcast directories.
http://www.burningdoor.com/feedburner/archives/001302.html
Update: It seems FeedBurner is getting a lot of support posts regarding their iTunes RSS. 1 + 1 = 2.