The ICE3 is an older model, and the Russian Velaro 'Sapsan' is an newer model, as far I know. There are 2 ICE3 versions, a `normal` ICE3 (this one can only run on 15 kV AC) and the ICE3M (this one can run on 15 kV AC, 25 kV AC, 3 kV DC and 1,5 kV DC). So the ICE3M is the version that runs here. At this:
http://www.flickr.com/photos/40012911@N06/3875529738/ picture, taken by myself in Emmerich (Germany, just behind the border with the Netherlands) you can see that there isn't a pantograph in use now. Here changes the voltage between the German 15 kV AC and the Dutch 1,5 kV DC.
But if there aren't locomotive changes at borders, it was possible to drive with more different locomotives on Russian route's.