new Registered user

It means your blog allows people to register as subscribers. You can turn it off if you don’t need it.

In your Administration > Options > General

Membership

* Anyone can register – Check this checkbox if you want anyone in cyberspace to be able to register an account on your blog.
* Users must be registered and logged in to comment – If this checkbox is checked, only logged in registered users will be able to write comments on your site.