Microsoft announced a new proposal called Simple Sharing Extensions (SSE) at their XML Development Center website. and there are also some applications I think will spawn from this new technology.. entrepreneurs and business minded programmers will find my these applications particularly useful
You can read more about these applications and the SSE model here:
It is certainly a very promising project to extend RSS via namespaces (so it remains valid XML) - and the licensing under the Creative Commons ShareAlike license (similar in concept to the GPL) is an interesting development - it is the same license as RSS so we may see some convergence in the future (maybe Microsoft would love to adopt RSS completely and have a control over its future).
I can see some decent adoption of SSE by businesses - it's biggest strength is making RSS bi-directional or even multi-directional - allowing for data to be updated from multiple sources.