Like many of Google’s products, Reader has gained a clean new look, with more space and less clutter, making it even faster to navigate your feeds. We’ve also integrated with Google+, so you can add a +1 to any item and share with your circles.
For those of you who shared items under the old system, you can export all your content from the Import/Export Settings page.
以前的共享功能貌似都没有了,全都绑定在G+,直接加1了:Sharing to Google+
http://www.google.com/support/reader/bin/answer.py?hl=zh-CN&answer=83000