It's not really rocket science. Malwaremongers are simply checking out top news stories from Google Trends Labs, then creating fake blogs with a bunch of keyword-heavy texts related to those terms. When an unsuspecting victim stumbles onto such a site, he/she will be greeted with a malware cake instead of the info they've sought. Usually, it's a link to a video; but alas, the site prompts you to first download a codec to see the video. The codec is, of course, malware/spyware or worse.
An example of this trend is the recent wave of phishing emails which aren't masking as PayPal or eBay, but as media sites such as CNN. Phishers just want your data, and if no one is gullible enough to give out their credit card number any more, they'll at least try to lure you into installing trojans by posing as blogs or news sites, which will ultimately result in the same thing.
All of this is not new practice, says Webroot’s senior vice president Paul Lipman. “However, the fact that these hackers are now manipulating Google’s methods for relevance to increase the ranking of these sites is new and greatly increases the number of people exposed to this threat.”