Some digging reveals Surrey NanoSystems as the claimed creators.

Their website: http://www.surreynanosystems.com/

Press release for VantaBlack: http://www.surreynanosystems.com/news/19/

Mid-2013 press releases [1][2] talk about using "vertically-aligned carbon nanotube (VANTA) arrays" and cite similar absorption rates as the linked article.

Okay, now I'm interested.

1: http://www.surreynanosystems.com/news/17/

2: http://www.surreynanosystems.com/news/16/