Update 3/10/2011: Extremely relived to note that as of today they added a little link to go back to the older happier days. The broad categories are enabled by default.

In a move Facebook will probably explain as a way to "make things easier" for companies, and possibly legal reasons (Targeting brand keywords like "iPhone"), they removed the capacity for marketers to target customers by specific keywords.That means it's a lot harder to target via specific interest, for example, an interest in "The Beatles" as a band, rather than the overall category of "Music". It's also impossible to ascertain and research different demographics which may have interest in a specific category.

I'm not yet sure if this is a test, but from what I know of their changes to their direct ads system to date (previous post), I have a feeling it's not.