[gorog]

No, they're centralized like Twitter. StatusNet is like the Wordpress of microblogging. Each Wordpress installation is its own isolated island. It's the same with StatusNet.

[mlinksva]

Not true, see my reply above. Users on different StatusNet instances can subscribe, reply, and fave each other.

You can see this in action at https://identi.ca/conversation/60337615 (which also points out some of the rough edges).