Here are some links to resources that describe AutoCAD 2013 and its new features:
Autodesk Japan release information (Google translation)
blog nauseam AutoCAD 2013 – What’s new? - future posts in category AutoCAD 2013
CAD-a-Blog AutoCAD 2013 is Announced in Japan!
Lynn Allen AutoCAD 2013 is approaching the Finish Line
Please post further links as you find them.