This threat seems a little overblown. From the description the target is PCs running SCADA software and specifically ASEM Ubiquity. Which they call “a platform commonly used in [ICS]” - yet this is a small (125 employees) Italian company that is dwarfed by the real industrial control players, including Siemens, ABB, Emerson, etc. Stuxnet worked because it had been very specifically crafted to install rogue code on Siemens PLCs which are widely used, but while Ukraine may be dependent on ASEM software, the rest of the world is not.
I agree this does not represent any real threat to a widspread power blackout in the US.