I ran across this article, but have not seen any mention of any major Google announcement anywhere.

Thank You, Google Overlords | TechCrunch

Running a website not optimized for smartphones? Guess what, you’ve been put on notice. Google is using its influence and the power of its algorithm to finally force web publishers to fix their mobile website configuration issues, or risk getting downranked in Google Search. Directing smartphone users to 404′s? You lose. Sending smartphone users looking for specific content to some generic mobile homepage? See ya. Using Flash for your video embeds on mobile? Farewell. Thank you, Google overlords.
Is Google's newest vendetta to attack sites with sloppy mobile implementations or lack of optimization for smart phones? Has anyone seen any further details about this?