No matter what it is called, this product continues to be the chief revenue source the search giant who advised they will keep modifying it whenever they detect a change in user interest.

A Google spokesperson told Search Engine Land:

Yes, I can confirm this rollout. We are always experimenting with the look and feel of our search result pages, including the delivery of relevant advertising. This is on English language domains now and rolling out to all languages and domains.

There is speculation that the reason for this change is due to the launch of Google Places which lead to a drop in users' preference for the title "Sponsored links". This was noted by Google after which they started testing the title "Ads" and it was saw a favorable response from users.

This change is only for the ads on Google search and not for the other Google products which feature ads such as Gmail.

This change adds to the many innovations Google has recently brought to its SERP (Places, Google Instant, Instant Preview etc), but I'm not sure that Google's advertising department will be too happy. Generally the word "ad" instills fear in some. Ads are a way for somebody to sell something to me, not a resource when I am trying to search for something in Google. Although it's only a minor change this might play on the psyche of some searchers. Could it result in a decreased CTR for advertisers?

Bing still labels its advertising "sponsored sites" and Yahoo! "sponsored results". I wonder if they will follow Google's lead and make the change.