I wrote a post back on February 1st, 2010 about the Two-Mile-Limit imposed on importing CAD files. I referred to these files as FOUS or Files of Unusual Size paying homage to the movie, "The Princess Bride". It has been mentioned quite a bit already but I wanted to update my own blog to reflect the latest development with the release of 2011.
The limit is now 20 miles, though you can still import the file. A warning is generated but the file will still be permitted, unlike before. You can read the blog post at The Revit Clinic called, "Revit 2011 2 Mile Limit Now 20 Mile Limit".