Didn't read the article, but the math they did about the R730 power draw is NOWHERE near realistic. A 1000Watt power supply unit (PSU) will only draw what is actually being used, not the full capacity 100% of the time. I have a fleet of R720's (generation before the example R730's) and their typical at-wall draw when running many VMs on them is about 150 Watts. So their math for that aspect is 100% WRONG.
That being said, neat concept IMO.