http://radio.weblogs.com/0001011/2005/01/15.html#a9204

Scoble has been fanning the flames around the copyright nature of blog material. Wearing my techno-legal guy hat for two secs... how about incorporating some sort of license metadata into the RSS standard... that's what XML is for isn't it? It's eXtensible for a reason.

This would allow publishers to indicate to aggregators how their content may be used- it's almost like DRM but without the big stick. Like an advanced form of robots.txt. It could allow things such as a copyright/attribution notice to be appended and so forth.