Here is the answer from GS:
TW2 and BIM Server will be available for EDU and University users and these are the basic restrictions:
ArchiCAD 13 EDU (Educational) version
An ArchiCAD file created in the Educational license can be opened by a full (commercial) license of ArchiCAD, which will then switch to Educational mode as long as the Education-license file is in use. The same applies to Education-version projects shared in Teamwork: if you join such a project using a commercial version of ArchiCAD, that version will switch to Educational mode. Projects shared by the full (commercial) version cannot be joined by team members using Educational licenses. The file extensions of ArchiCAD files created in the Educational license are identical to those of files created in the Commercial license (i.e., PLN for a "solo project" and PLA for a "solo project archive"). However, if you print a file created in the Educational license, each printed/plotted page will display a watermark text.