Google ads unethical or just clever design?

Jakob Nielsen's latest Alertbox is sure to get some defensive responses from the folks at Google...  He publishes results from a recent eye tracking study that clearly shows that users do not look at banner ads on web sites at all when they are looking for information or engrossed in the content on the page.  This isn't particularly new information, we've known this for a long time, but he does take it a step further.  First, he explains that there are three main design elements that are effective at attracting eyeballs to online ads (Plain text,  Faces and of course Cleavage and other "private" body parts).  Then he goes on to explain a fourth design element:

In addition to the three main design elements that occasionally attract fixations in online ads, we discovered a fourth approach that breaks one of publishing's main ethical principles by making the ad look like content:

• The more an ad looks like a native site component, the more users will look at it.
• Not only should the ad look like the site's other design elements, it should appear to be part of the specific page section in which it's displayed.

This overtly violates publishing's principle of separating "church and state" -- that is, the distinction between editorial content and paid advertisements should always be clear. Reputable newspapers don't allow advertisers to mimic their branded typefaces or other layout elements. But, to maximize fixations, that's exactly what you should do in a Web ad.

A specific ad may or may not be ethical, depending on how closely it masquerades as content. I caution against going too far, because it can backfire and mislead users. Unethical ads will get you more fixations, but ethical business practices will attract more loyal customers in the long run.

It doesn't take a genius to figure out that he's taking a shot at Google here, because they're obviously really good at making ads look like native site components on their search results pages.  My question is if it's really unethical or just clever design?  How will we know if users are annoyed by these ads, or if the relevance of the ads makes it ok in their minds?  I would be interested to know what kind of answers follow-up qualitative research might uncover.  Eye tracking by itself won't show you how people are feeling about these ads.  My guess is that users wouldn't care as long as the ads are relevant...