In my opinion, the Yahoo MediaRSS namespace is a useful and lightweight extension to rss2 - It just adds some machine readable info about your media to the feed and more and more apps for it are coming up: Just have a look at cooliris and surf to my blog (or google images search results if you don't like my photos ;-) - THAT's nice.

I already implemented media rss in my PhotoBlog plugin YAPB - and since i plan to build more upon core WordPress media functionality in future, i'd love to see that feature in the core.

Greets from Salzburg!

Johannes