In an effort to keep organic search results clean from content spammers and to strengthen the Google Plus Social Platform, Google silently removed the Plus One button. The new feature has a more solid Javascript and “forces†users to “share if they really like†a particular item in organic search results. This increases the level of “authorship†towards the specific share and attempts to discourage pure Plus One spamming. Thanks Sabya
Buddy, that's a pretty old update, the same was implemented by Google in July, here's ma post on the same -http://blog.seo-first-page.com/2012/07/google-update-replaces-1-button-with.html