you can either import the old mapping into 2.0.3, which in most cases works flawless (only few custom mappings had issues) OR you use the mapping that is installed along with the 2.0.3 version. it's in the default settings.
When you block a person, they can no longer invite you to a private message or post to your profile wall. Replies and comments they make will be collapsed/hidden by default. Finally, you'll never receive email notifications about content they create or likes they designate for your content.
Note: if you proceed, you will no longer be following .