Blogger with its last update finally included the ability to have inline comments in a blog without using a third party commenting system. Almost all commenting systems in the past had a form for you name, email, and URL. So blogger as usual does it differently. People can choose to entered Anon (if the blog allows it) or select their blog profile. So if you are not a blogspot blogger you would have to create an account at blogger and then create a profile to show. If you maintain a blog using a different publishing system, then just too bad as far a blogger is concerned.
The commenting system does not use a popup window and it takes you a couple more steps than normal to get back to the blog you were reading. It just makes you wonder what kind of research they did and why they made it so difficult. When they added syndication did they use a standard RSS? No they used ATOM which is still not supported by many aggregators. Did they add the ability to do trackbacks? Again no and I am afraid of what kind of system they would implement to do so. If you are a blogspot user and want to trackback to another blog here is a form that allows you to do it.
So if you currently have a blog and a working commenting system and have thought about using bloggers new one instead. I would advise you to stay with what you have.