YouTube's New Comments System with Google+

 Similar to the Facebook News feed, Google has included a setting to switch back over to the most recent feed of comments. However, when a user clicks on a different video, the default view will change back to the top rated comments. Regarding comment management, the video creator also has a new set of tools to use when moderating the comment stream.

Announced  November 6, 2013 on the official YouTube blog, the YouTube development team has integrated the site’s commenting system with the Google+ social network. Originally announced during late September, this transition is an attempt to move more relevant, high-level comments to the top of the feed while pushing less helpful comments down into oblivion. By displaying the “Top Comments” by default, users will be shown comments from the creator of the video, comments that received lots of positive votes, comments posted by public figures and comments posted by friends within a user’s various Google+ circles.


But some YT user don't like this it removes anonymity , because activity here will be on display to an audience that  have not chosen.

Here’s more detail about the new YouTube comments powered by Google+:

• Comments you care about move to the top: You’ll see posts at the top of the list from the video’s creator, popular personalities, engaged discussions about the video, and people in your Google+ Circles. You can still see the most recent comments by switching from “Top Comments” to “Newest First.”
• Join the conversation publicly or privately: You can choose to start a conversation so that it is seen by everyone, only people in your Circles, or just your bestie. Like Gmail, replies are threaded so you can easily follow conversations.
• Easily moderate comments: If you also post videos on your channel, you’ll have new tools to review comments before they’re posted, block certain words or save time by auto-approving comments from certain fans.