In Germany we just started to take that Bachelor/Master/Phd system. Our system is between B/M (Diploma) and M/Phd (Doctor). So the change is sometimes not compatible with the way we study and learn. But here the three main universities:
—Germany-Weimar—
Media Art and Design – Master of Fine Arts (M. F. A.)
http://www.uni-weimar.de/cms/index.php?id=31&L=1
It includes Interaction Design and you can take courses of other genres like ID, Graphic Design, Fine Arts or Architecture. In Weimar/BUW you have a project based and very interdisciplinary study - old Bauhaus style.
—Germany-Berlin—
Experimental Media Design - Master Course?
http://www.udk-berlin.de/index.php?cSID=1ab907d3665b6144f5a89977717ab0d2&ELEMENT=9377&template=startEnglish
Im not sure if its a standalone Master or a later upgrade course. I didnt understand that website. In general in Berlin/Udk they have a class system, like one teacher for several years. At Experimental Media Design this is Joachim Sauter of Art+Com.
—Germany-Cologne—
Audio-Visual Media, Master of Fine Arts?
http://www.khm.de/programme/index_e.htm
In Cologne/Khm they have a wide spreaded focus, but in fact this is your choice if you go to a very artistic, experimental way of interaction design. More art than design. You have to check individually for a master - write them your artistic ideas/ways.