A WebmasterWorld thread said one of the policies seemed interesting because many sites do it. It is this one:
Is placing a 300x250 ad unit on top of a high-end mobile optimized page considered a policy violation?
Yes, this would be considered a policy violation. This implementation would take up too much space of a high-end mobile site's first view screen with ads and provides a poor experience to users. Always try to think of the users experience on your site - this will help ensure that users continue to visit.
So if you depend on AdSense for income, you should 100% read through the new FAQs immediately. There is a reason Google posted this and called out specific policies.
Forum discussion at WebmasterWorld.