Update: A Google spokesperson tells WebProNews: "Like you wrote up in your article, it's not new. Search plus Your World builds upon existing search features such as Social Search, personalized search, and authorship. You will continue to see existing Social Search features including +1s and content shared by your connections on Google+ and other sites. We’ll continue to look at your Google+ profile to see other content you’ve published online and linked to your profile."
He shows a screen cap to back up his claim. It's not the People and Places box or anything, but it does appear to show a social search result from Twitter, very similar to the recent injection of personalized Google+ connection results.
I'm not sure this is the result of any new offering from Google. They've had such social search features long before SPYW. See the "Social Connections and Content" section of your Google dashboard. This is basically the same connections you have listed on your Google Profile. So if you have your Twitter account connected, Google has that information, and can deliver you such results.
It's not exactly the same as having access to the Firehose, which would blast all tweets into Google's index in real time.
That said, SPYW has pretty much dominated those personalized search results with Google+ connections since it was announced, though Google made it clear, that it does in fact draw from other open web sources.
Still, Twitter raised a big stink about the whole thing, claiming Google was making Twitter results less visible. Many criticized the lack of non-Google sources in the People and Pages box in particular.
There have been reports of the relationship between Google and Twitter souring. Apparently the companies were supposed to have an Android-related conversation at the Consumer Electronics Show last month, but that didn't happen, as Google's SPYW raised the aforementioned stink.
It's really not clear if this finding from Lurie is the result of any new developments. My guess is not. We've reached out to Google for comment, and will update accordingly.
Either way, it does show that Google will still show personalized Twitter results in some cases. That said, given Google's increased emphasis on freshness, that firehose would be a lot more helpful.