A WebmasterWorld thread has several Google AdSense publishers reporting they received a message from Google to place ads at the top left of their content in order to increase ad exposure, clicks and obviously earnings.
I confirmed Google sent out this message to publishers, here is a copy of the message I received myself from Google AdSense on Wednesday:
Now, if you listen to this advice, which says, "Highlighted above is an area on the page where we think a new unit would have the greatest return," it can and should lead to a Google penalty.
We've heard complaints from users that if they click on a result and it's difficult to find the actual content, they aren't happy with the experience. Rather than scrolling down the page past a slew of ads, users want to see content right away. So sites that don't have much content "above-the-fold" can be affected by this change. If you click on a website and the part of the website you see first either doesn't have a lot of visible content above-the-fold or dedicates a large fraction of the site’s initial screen real estate to ads, that’s not a very good user experience. Such sites may not rank as highly going forward.
I know they are separate departments, with no ties. But in no way should one Google department be telling you something that can hurt your search rankings.
This obviously also has repercussions on the Panda side of things as well.
Forum discussion at WebmasterWorld.