Dave Winer has announced RSS 0.92 a forwards-compatible modification to RSS 0.91 to support new software from UserLand called "My.UserLand On the Desktop".
RSS 0.92 makes the language element optional and introduces some new elements:
cloud describes a system for subscribing to updates of the RSS file
enclosure describes a large external file to be sent with the RSS file
As Dave has said he is "not doing this as part of a working group, or in collaboration with anyone else."