Over the course of a 24 hour period, there has been an increase in reports that Google AdSense has been placing the arrows on many more AdSense ads. We call them scrolling AdSense ads and we first reported Google testing them back in December of last year.
It seems like Google may have made this feature a default for all standard Google AdSense ads. Here are two examples from two of my sites, which did not have the arrows on them beforehand.
Maybe the scrolling feature worked so well that Google decided to add them to all of their ads? It would be nice, as a publisher, to be given the option to show the arrows or not.
Update: Google has just (3:30pm (EST)) confirmed that all AdSense ads now have the scrolling feature. Google said:
After months of testing, we've just updated our text ad format to include 'next' and 'previous' arrow buttons for cost-per-click (CPC) ads. When a user clicks on the 'next' button, an entirely new group of ads will appear in the ad unit, giving your users greater control over the ads they see and click.
I love finding these things out before it is officially announced.