Searched a bit and acnt found anything about that topic.
Since Facebook alow to export Insight data from Fanpages it would be great if we could import that data to piwik . Since Google analitcs dont offer a feature to import it would be a great Plus .
for the start a simple file upload would be good
Final with a facebook connect auto batch import would make piwik to the main Stats tool
As all Fanpage and Webpage stats in one place no switching between different profiles or 3thd party pages .
Sorry my knowlage of Sql is too limited to make it by my own but probably it inspire some one .