Adblock Plus doesn't deal with ad companies. But with websites that have ads on their site. So if the kind and placement of ads on their website is "acceptable" they can get on the white list. The article in the link of this thread is a little confusing. It's not true that all Google AdSense ads are white-listed, but the ads on the Google search page are.
By the way Adblock Plus has put Reddit and some other smaller websites on the white list for free to support them. But unfortunately Adblock Plus has also to cooperate with larger companies to make some money, themselves. But still, all ads that are getting on the white list are mild, and not the kind of ad that made once everybody of us that pissed off, that we started to use ad blockers.
Another thing I would like to mention is that, around the same time Adblock Plus introduced "Acceptable Ads", a lot of websites at least here in Germany started to detect ad blockers and asked the user to disable his ad blocker. Otherwise the website refused to deliver content or provide functionality. With the increase of popularity of ad blockers, the people running websites driven by ads will no longer tolerate that their ads are blocked. And there will be probably nothing you can do against that. Considering that, it is actually great that those websites can just get on a white list used by the majority of AdBlock Plus users. So the websites can continue to make enough money from their ads and people that are smart enough to disable "Acceptable Ads", like you and me, still get all ads blocked.