It seems that G is playing around with ads directly above the serps (not to the right). Less competitive keywords have no ads above, with more ads when the competition increases.

This may not be something new, but they have changed the scale in our favor. I have keywords with 1-2m competitors that use to have 3 ads above it which now have none!

I would say maybe it is due to not enough money being put into the ads, but there are about 10 different competitors that spend up to $5.00/click for this term. Their budget is not up for the day as their ads are still there, but to the right.

Hopefully they keep it this way and we all get more traffic as a result!