Emotiv Systems' device is described as "a high fidelity neuro-system that redefines the realm of human-computer interaction". Lord save us. The headset apparently provides opportunities for development with various software suites, including "The Expressiv suite, which can identify facial expressions in real-time, the Affectiv suite, which measures players' discreet emotional states, and the Cognitiv suite, which detects players' conscious thoughts," according to that Gamasutra report.
The GDC showing is a launch event, so pricing information should be available this month. It's the beginning of the end. They'll be stealing your credit card numbers by mind control and laughing at your stupid sex thoughts next.