Just this morning Google adsense was seen adding favicons to text link ad units. Just see what I saw today on my own blog. It is mixture of the ad links units and the regular text ad units.
This seems to be a mixed solution which caters to lovers of both ad links and ad units. It seems to describe the ad links better with the text “Change to Ads about” which gives better indicator what happens when you click such links.
Another thought is that they occupied the top position on the first ad unit. Does it mean such ads links will be higher paying than corresponding lower ad units? Or simply the first ad has moved to second place but is still the top paying one?
It does seems to be a way to give better visibility to ad links. But it does disturb the visual balance of the ads, making the ad disbalanced and less appealing!