Interesting - Phil Ringnalda says he's going to have a few problems dealing with the new List element MS introduced:

That title element in the cf:sort element is the one with teeth. My SAX parser goes along, notifying me whenever an element is opened, and again when it is closed, and when the channel opens I say $in_channel = true;, and leave it that way until I see an item open. Then, when I see a title element, if $in_channel is true I use its content as the title for the feed, so I'll wind up calling that feed "The title of the item." And since I didn't invent that style of RSS parsing, I'm not going to be the only one getting bit.

Well, I don't think I run into that. I use the VW XML parser to create a document object, and I then walk through that to get the elements of interest. The only thing that causes me difficulty there is my own issues with understanding specs :)