trouble making a copy of inputGeom in a custom deformer

[Daniel Lindsey]

I'm trying to make a copy of my inputGeom

MObject myInputGeomMesh = inArrayHandle.outputValue().child(inputGeom).asMesh();
MFnMesh tCopyMesh;
MFnMeshData inputFnMeshData;
MObject copyMeshObj = inputFnMeshData.create();
tCopyMesh.copy(myInputGeomMesh, copyMeshObj);

I'm then hooking this into an attribute I've created that accepts kMesh, but the issue I'm seeing, is when I update the positions on this mesh, since it's only in memory Maya isn't updating anything else about the surface.  I'm trying to figure out how to make and actual copy of the mesh, similar to the ShapeOrig, so that I can do what I need to this mesh, and have it update as expected.  Any help would be great.