Blogger has recently released a feature that lets you publicly subscribe to other blogs. Google calls this "following" and you can only follow blogs powered by Blogger, at least for now.
"Do you have a favorite blog and want to let the author and readers know that you are a fan? Well now you can do that and more with the Blogger Following feature," explains the help center.
Bloggers can add a widget that lists the people who follow a blog. Visitors can follow a blog from the widget and see their subscriptions in Blogger's dashboard or in Google Reader.
In most feed readers, subscribing to a feed is an anonymous action and the only public information is the total number of subscribers. The new Blogger feature indirectly adds public subscriptions to Google Reader.
Googler John Panzer has more details about the next steps:
"The Followers gadget lets you surf the network of people who read and interact with blogs. Just click on any of the followers and you'll go to their profile. For now, that profile is just their Blogger profile page with the blogs they own... but down the road, we'll also be integrated with Friend Connect. Which will open up this network further, in a couple of ways: A non-Blogger site can add a Friend Connect gadget to show the people following it; and you can filter the followers of a blog to show only the friends you already have on your favorite social network. Which you can view as extending your social network out into the blogosphere, or as the blogosphere incorporating all social networks -- take your pick. Of course all of this is based on OpenSocial, so anyone will be able to add gadgets and talk the OpenSocial protocol to access, with user permission, all of this network data and do new and interesting things on top of it. This represents a natural evolution of the loosely joined, standards-based pieces that have always characterized blogging."
The "followers" feature is not yet available for all Blogger users, but you can enable it by following a blog. The address is:
http://www.blogger.com/follow-blog.g?blogID=<BLOGID> (e.g: follow Google OS).
There are two options: follow the blog publicly and appear in the list of subscribers or subscribe anonymously. In both cases, the blog will appear in Blogger's dashboard and in a read-only Google Reader folder
that can be hidden in the settings.
Instead of building a social network like MyBlogLog, Google creates an application on top of other social networks. Incidentally, the application is first tested for blogger.com, but a future Google Reader API and the migration to OpenSocial/FriendConnect will make it look more interesting.