It's Google Reader's turn to get the Google+ treatment as the news feed tool gets a new look and the ability to +1 items, Google said in an official blog post. In order to simplify Reader, Google will turn off the comments, following, friending and shared items functions because those things can now be done in Google+. The search giant also announced they were going to release an Android app very soon.
Reader items that people want to share now can go through Google+, and that way, the items can be shared with only the people you want to share it with. That's the whole idea behind circles anyway, so everything you share doesn't go to everyone you are connected with. Google+ launched in June, and it's been so popular, even Facebook has changed its layout to mimic the circles function. Facebook lists don't let you share only with who you want, but at least you can break down what content you want to read in a similar way.
Additionally, Google seems to know that many people have grown quite accustomed to Reader and that those same people may not want to use the new layout at all. Google wants people who decide to scrap Reader because of the new layout to consider using the subscription export feature. Google wants you to be able to take your data with you. If you go that route, you'll be able to take shared items, friends, starred items, likes and subscriptions with you.
In the new Reader interface, the +1 button is going to be right next to the star button. This is the first update Reader has had in a long time, so perhaps Google knew many users would not like the changes.
Tell us in the comments if you were really into the old Google Reader and are sad to see it go.