OK, So really the only usage for using the actual class command w/ the first capital letter for these Abstract Base Classes is to cast an already existing node into the pymel object.
But, some classes can create the node from scratch like: jnt = pm.nt.Joint(n='root') > Option1 (I like doing this in code if I know what type of node I need > because it will fail loudly if I give it something unexpected): John, I too like to create my nodes w/ the explicit capital'd classes whenever possible to fail early and often. -- http://groups.google.com/group/python_inside_maya
