Do you think Google will use filter Adsense / Content Ads into their algo?
After all if your site hosts these ads then it's pretty relevant to that keyword range / sector and would be a sound business move for Google.
It would encourage webmasters to categorise their own sites, without spamming - the more relevant your ads are to your visitors - the more money you will make.
Just a random thought! :)
Added: It could also explain the recent weirdness - it would no doubt be an enormous undertaking for Google to intergrate such a system into their algo.
They could have test run it with the initial content ads release (only a few, high traffic sites), then launched it mass market...