This is a great idea and I agree with all of his goals.
There’s no need to create a new directory, though! Syndic8 has been tracking the use of Creative Commons licenses since April of 2003.
Full information can be Creative Commons license usage can be found on the Syndic8 RSS Statistics Page. Scroll down a bit to see the license usage stats. As you can see, not that many feeds are using licenses yet.
I would be happy to support an effort to get more feeds marked with licenses.