Maybe if you RTFA you would notice that it is a bit more complicated than that. The organization or individual who went after the centrifuges infected at least 5 different companies. An electric company, a steel manufacturer, 2 different industrial supply companies and a military importer /exporter company. These targets were all brand new infections, not passed from org to org. So they would have had to break security at at least 5 firms independently. Not too shabby.
You should read the second link, because it is quite fascinating. Who ever did it exploited the servers directly (as opposed to laptop vectors or smart phones or whathave you), and even went so far in two of the companies as first infecting the virus scan servers (one machine named kaspersky, another avserver...). Must have been awfully ballsy and confident about their viruses stealth.
So we have learned that it was a directed attack, over multiple targets, the initial infection was most likely delivered by network access and not by USB.
I think your summary misses most of the interesting parts. The name of the one company with hardly any context would not have added to the slashdot summary at all and would most likely make people miss out on nice simple deconstruction which the second link provides.