@netmeg, which is the reason why I'm suggesting all this ad discussion is completely relevant. It is very prudent, yet very malicious for Google to poison the minds of all webmasters regarding too many ads. Afterall, since Google climbed to success, the push was always more ad units! MFA was a self imposed spam issue. If this wasn't a bunch of S then Google would change the adsense policy to a REDUCED number of ads. Again, Cutts doesn't run Google and issue directives.
We need a poll here. Who has removed ads and affiliate link this year. Who believes that ads affect organic traffic? That there is the true and most relevant issue that regulators may need to look at more closely in the future. For this very reason I don't think you're going to hear anything about ads affecting rankings. Say enough to scare or plant a seed and the mission is accomplished. Don't think for a second that Google cares if some webmaster reduce ads. I suggest they don't have a shortage of "billboard space". Obviously they don't.
If Microsoft was smart, they would do a search ad program. For that I would put it on every site I own. I would only have the one. If you catch my drift.