New Data Nuggets
Web analytics may not necessarily need another metric but +1 button promises to help measure engagement. Official details on what data will stream from Google's +1 button are not available yet, but Jim Prosser from Google confirmed to SEW that "we're bringing data to Analytics, Webmaster Tools, and AdWords frontend soon".
Nontheless, there are methods of tracking +1s to your pages. By writing your own Javascript function, you can track +1 clicks as a Google Analytics event using _gaq.push() and use GA's standard reporting functionality. All-in-all, the +1 button will now become another micro-conversion that may provide insight to how your site is performing and how users are engaging with your content.