Good post, Will. This feature is no doubt great but I believe, it'd be helpful for aggressive bloggers whose major income comes from adsense. They can simply pick up the best topic and draw good number of visitors with a small interesting post. And I'm sure, this kind of post can work as a link-bait post too because it'd be like a news or some interesting snippet in demand. So, Google hottrends can help in bringing some good backlinks, indirectly. Just my humble thought. And as you already commented that it'd wouldn't be a great idea to create a website targeting them. I share the same thoughts when I looked at it.