Many publishers have report that they have received emails from Google about this program. The main idea is to to group publishers into groups of similar categories so that advertisers can target them easier and allows so called brand-advertising. Here is a copy of the email: Did you receive this email?
That's their top level domain, they got a Google blog with URL: google.blognewschannel.com . I wonder if Digital Point is invited. But they would have to add in medium rectangles some where in order to join.