Things are running a little behind where I had hoped but I should see the Zeiss 135mm f/2 APO-Sonnar by mid-February.
The Zeiss 100mm f/2 Makro-Planar and the 135 f/2 APO-Sonnar are siblings and can be expected to share some similarities, but they might behave more differently than is obvious— a Makro-Planar is not a Sonnar.
While the new 135m f/2 APO-Sonnar can be expected to be better corrected for axial (longitudinal) chromatic aberration, the 135/2 APO is not a macro lens (1:4 vs 1:2 for the 100/2 MP). And so the areas of close-range and distance performance as well as distortion and flatness of field should be an interesting area for exploration.
Furthermore, 135mm is not 100mm and the 100mm f/2 Makro Planar is actually close to 97.5mm in true focal length, so there is a ~38% difference in field of view.
B&H Photo now has the Zeiss 135mm f/2 APO-Sonnar available for pre-order.