I think your definition of "content" is too expansive in this context. Just because it's on the page doesn't mean it's content. Skype/MS saying that the presence of in-line ads will foster conversation is much different than sponsored or side results in Google SERPs.

He meant the ads are in line with the content. The fact that it's an ad is certainly highlighted but it is intentionally subtle.

They aren't interspersed except at the page level. It's not the same thing.

I don't know how Google show up for you, but when I do a search for a term such as "cars" I get ads that appear very similar to the actual search results at the beginning and end of the same list. In fact all the high contrast features are identical between the two, and it is only the lower contrast features that distinguish the ads from the results.