New Transient Suppressor Manufacturer
A new family of ultra-low capacitance Transient Voltage Suppressor (TVS) products was released earlier this year from Alpha and Omega Semiconductor, Inc.
They have products that meet IEC61000-4-2 Level 4 specification for electrostatic discharge (ESD) protection (8kV for contact and 15kV for air discharge).
They also have products that provide protection to 15kV for contact and 18kV for air discharge, which far exceeds the IEC61000-4-2 Level 4 specification.
Capacitance is as low as 0/9pF. I'd agree that this is ultra-low for TVS devices.
These products are worth looking at when protecting parts of HV systems from such transients as arcs, lightning, and pulses. See http://www.aosmd.com/