The use of HTML entities in Google's search results in order to make your snippets stand out is nothing new. We've been reporting on it for literally ten years. We've seen it in sitelinks and AdWords and we've even seen webmasters experiment with emoji characters.
Sean Murray noticed Google allowing HTML entities to be displayed and posted about it in Google+. You can see it yourself on many (not all) browsers and operating systems by searching for [✨].
Here is an example of a snippet with this working:
Typically, Google will disable this from working going forward but we will see.
I added it to the title tag of this page to test.
Forum discussion at Google+.
