Google announced today that it is adding Google+ hashtag support to Google Search. If you search for a hashtag on Google, it will show results from Google+ on the right-hand side of the results page. You can then click over to see more on Google+ itself.
Googler Zaheed Sabur made the announcement in a Google+ post:
Just imagine how useful this would be if Google still had access to the Twitter firehose. Facebook integration would be pretty nice too, considering they recently rolled out hashtag functionality.