Here are some design mock ups that have been created. While GNU social will come with many styles, developers and users will be able to design new styles easily, with CSS.
Big news! StatusNet, Free Social and GNU social projects merge under GNU social name. Mikael Nordfeldth (Free Social) and Matt Lee (GNU social, GNU FM) will be co-maintainers.
Matt went to the Federated Social Web Summit in Portland, OR and met with Appleseed, Diaspora and Status.net developers, amongst others.