Google shows a new annotation next to some web search results and image search results: “actively discussed on Google+”. If you click “show”, Google displays a recent Google+ post that includes the URL.
The feature is potentially useful, but it needs some fine-tuning because the Google+ posts aren’t necessarily popular, while some search results don’t need special annotations.
It’s interesting to notice that Google+ popularity is a ranking factor for Google’s search engine even when you’re not logged in.