This is a apparently what came out of a series of focus groups, the overwhelming message from which was that users wanted to de-clutter their feeds. From the blog post:
We came up with the idea of multiple feeds, each with its own focus on a particular topic, type of content, or type of friend. It was a good start, but crucial questions remained: which feeds to offer, and which stories to put into them?
I gave each participant a stack of recent stories from their feed, printed out on paper, and asked them to pick out the ones that interested them and discard the rest. Next, I asked them to sort the remaining, interesting stories by putting them into piles separated by what they liked about each. An analysis of participants' piles and the stories they'd put into them yielded clear themes.
And—voila!—the new news feed was born. Actually, the post is an interesting look into how Facebook researches its user experience, and is well worth reading if you care about how data is delivered to your eyes. [Facebook via Engadget]