Yup! It's neat and have certain better features over Google Blogger's traditional commenting system.
I've imported all of the previous comments into it as i didn't want to lose those precious comments.
It's all the same. You'll just have to write a comment, click "post as" and select "google" from the list of many online accounts and viola! You are done!
If you want it for your own blogs too, click Disqus