For some reason i had missed the Facebook Newsfeed preferences dashboard until today. It looks like it has been around since November 06. If you check out the announcement post it highlights some of the features of the Dashboard.
First i love the design- and agree with Larry Rubin's statement that whomever designed this feature could have been inspired by music mixing stations- very cool and easy to use.
Second, i only have 66 friends right now-but realistically see that number rising. Some are 'real' friends people i hang with all the time, others are people i like to follow in the industry or coworkers, and even people i meet at events that i might want to keep in touch. As my Facebook feeds start getting noisy- i am going to love the ability to not only indicate the types of stories i would like to see more or less of but also identify which 'friends' i want to see more and less of. love it- i can tweak my feeds based on what my attention needs are.
The reason that Facebook is able to easily do this is because of the metadata that is applied to each data element. Story types (Events, Groups, Statuses etc.) and who posted (friends). So they are taking well structured content and applying a good UI design that is easy to use for most users. Can't vouch for the results yet however.
This will also be extremely useful once (and if ever) Facebook allows you to publish your News feeds as RSS- instead of taking the whole universe of feeds you can already add some relevance post syndication and then other tools take it from there.