"Instead of having the extruder, which is where the build material is expelled from, move on all three axes, they have changed the mechanics around quite significantly. The MOD-t 3D printer will feature an extruder that only moves in the Z direction, while the build plate will move in the X and Y directions."

The MOD-t movement isn't special. That's how a "knee" or quite a lot of vertical mills are setup. The down side with how they show it is that the machine envelope is needlessly large, or it further constrains the XY build area.

I don't know what cartesian 3D printer moves the extruder in all three axes. Maybe it's common in the big-name high-dollar machines. A Mendel-type is often set up to move the extruder in the XZ axes, and moves the table in the Y. Makerbot & Ultimaker move the extruder with an XY gantry, with a Z platform moving.