purplecape - 2:03 pm on Mar 28, 2008 (gmt 0)

I don't see this as about-face--as others have said, it's clarification. Blending in the past--and in some of the Help pages you can still find--was talked about in VERY general terms, along the lines of "Use your site colors so people don't ignore the ads."

That still holds true. What they are saying now is that ads must not be set up in an identical manner to content or navigation--yes, you want visitors to look at them, but not to confuse them with site content.

I would think that most site owners already comply with these guidelines, which I think are a WELCOME clarification. We now have some much more specific guidance as to what is OK and what is not.