RSS Version 3?

Real Simple Sydication Version 3. RSS 3 Lite has been drafted, to provide yet another feed format on the Internet. Why oh why? And where can I find the "compatibility" mentioned? Ain't the whole idea of XML about how you can build on top of the existing standard, provide compatibility, by mixing tags with different namespaces together? And this is right after Atom 1.0 was announced last month, which was again incompatible with previous versions? I pity the feed parser and news aggregator developers.