Needle-Stich script is modified English Roundhand (Copperplate). In Joe Vitolo's case, it is modified Engraver's script.
This style of Copperplate(or more exactly,Spencerian) is called the "Needle Stitch Script"(as showed in the picture).
It has nothing to do with Spencerian script which is entirely different.
Maybe you are wrong this time,Ken.I recommend you to have a look at WHAT I had posted above:http://www.iampeth.com/books/sull_volume_I/sull_volume_I_page24.html
And you will see the sentence which reads"A form of Spencerian in which short interrupted dashes of shading are added to a unweighted script...."
So, you can't say that it has nothing to do with Spencerian.
I would say it has to do with neither, exclusively, but is rather a process which can be applied to any shaded hand. The example you posted, is, as Ken correctly points out, based on Copperplate, whereas the example on the page you cited is Spencerian.
Yeah,to be exactly,NSS itself is not a style of script,but a technique which can be applied to any shade styles.