Today, a new section was added to the wordpress.com support documentation entry for Advertising:
3. We are testing a feature called Ad Control that lets WordPress.com bloggers with a lot of traffic and appropriate content turn on AdSense for their blog and split the resulting revenues 50/50 with us. If you’d like to apply to try Ad Control and you get over 50k page views per month, please email email@example.com
Hmmm … there’s not a whole lot new here for most wordpress.com bloggers. VIP hosted blogs, which garner that many monthly hits and even more have been able to run Adsense on their blogs for two or more years now.
Content guidelines: Publishers may not place AdSense code on pages with content that violates any of our content guidelines. Some examples include content that is adult, violent or advocating racial intolerance.