Now you can restrict reader access to your blog, with new privacy settings to allow you to create a 'subscriber list' of sorts to any blog hosted at Blogspot. The default settings for Blogger allow anyone to read your posts, but the new "Blog Readers" tab allows bloggers to only allow readers they choose (via email address). Also included in the Blogger feature update is the ability to "label" posts, which is essentially "tagging" or categorizing posts. Other additions include new templates and the ability to add photos more easily.
You can read more about the upgrades at the Google Blog.