Default font size increased
They have implemented the change already...
As a follow-up to last week's launch of font size controls, we'd like to let you know that we've just increased the default font size for AdSense ad units. This change will affect your ad units if you haven't yet customized your font sizes, or if your ad units are set to 'AdSense default font size' -- you'll notice that the text in your ad units is now the equivalent of 'medium' instead of 'small'. We decided to make this change based on publisher feedback and our testing, which showed that this increased font size improved performance.
Inside AdSense: Default font size increased