http://adwords.blogspot.com/2009/03/new-insights-for-search-features.html

* New data sources – We've added additional data from Google News, Image and Product Search sites so you can see what the world is searching for beyond Google Web Search. For example, retailers could use the Product Search filter to get a better understanding of what people are more likely to buy, and then stock the appropriate products.

* Category suggestions – Ever wonder what other categories your search terms might be classified under? Insights for Search now suggests category breakdowns for your terms. For example, if you type in the search term "apple", Insights for Search will show you all the relevant categories searches are classified under such as Computers & Electronics, Entertainment, and Food & Drink.

* Metros for the U.S. – You can now drill down to specific geographic regions, or metros, to see how search interest levels vary. This can help you with geo-targeting in your AdWords campaigns.