levo - 3:10 am on Jul 5, 2013 (gmt 0)
A couple of new (or updated?) support pages;
What is sabotage and how to prevent it
Opt out of new ad formats
Best practices for ad placement
Google is definitely pushing for differentiation between ads and content, reversing its old position.
Choosing ad colors that complement your site is great, but avoid aligning images with your ads or making nearby content mimic their formatting. Displaying ads in these ways isn't permitted by our program policies.
Also check the 'ad mimicking' example. I've been doing this because my account manager suggested it 4 years ago.