YouTube will now be using Google+ to moderate all the comments on the video. The change is said to improve the display of the comments that users would want to see the most. The posts verified by YouTube or Google+ will be pushed to the top in the comments thread.
The change will put comments from popular users, video creator, and users in your Google+ circles at the top of the comment threads and comment section.
Users can also comment on existing comment thread by using Google+ account with private or public settings. The private setting will only let the people in your Google+ circles (chosen by you) to see your comments.
The new feature will also allow automatic approval of comments from known users, block inappropriate words, and review comments before they get published. This will certainly help the YouTube users who spend lot of time in moderating comments.Google Utilizing Google+ in YouTube for Better Moderation!,