Dave Winer: Here’s a look at the “photocasting” feed format that Apple introduced yesterday. It’s fairly bad.
It’s not quite valid.
Either they are improving it in realtime, or they are down to three basic errors: incorrect mime type, they provide a feed level id (something Atom requires and RSS 2.0 doesn’t directly have support for), and use nearly RFC 3339 formatted dates (again nearly Atom).
If they are going to go this far, why not go with Atom? ;-)
Oh, and some documentation for the wallpapers namespace would be nice.