You may be interested in a discussion concerning the practical
implementation of RDA that has been going on in the Autocat list under
the topic "RDA, AACR2 and a simple, commonsense implementation plan."
The secretary of the JSC replied as well. I replied, mentioning the
Cooperative Cataloging Rules.
You can check the blog at http://coopcatwiki.blogspot.com/2010/02/rda-aacr2-and-simple-commonsense.html
for my post.