If you are looking for a plugin to manage all your blogs. If you are having more than 2 blogs and you receive good number of comments, I am sure, it would be tough for you to go through all the blogs and moderate all the comments. With Kish Multi Pro, you can moderate comments of all your blogs from a single page.
Besides approving / deleting / editing comments, you can even reply to comments, send personal reply via email using this plugin
Kish Multi Pro is not just for doing new Posts, but it can be used as a Comment Moderating Tool. You do not need to login to all your blogs to check for pending comments or reply to the comments.Here