So it looks like the Profoto D2 didn't hold the title for the "world's fastest monolight" for very long. Today at Photokina, the German-based Hensel just announced the Cito 500 -- an even faster light with flash durations as low as 1/100,000 of a second and a burst rate of up to 40 flashes/sec. By comparison, Profoto claims 1/63,000 and 20fps.
The Cito is a 500ws monolight with a 9-stop range (500J down to 2J), a 300W halogen modeling lamp and a built-in receiver. However, it does not do HSS or TTL -- which the Profoto does (as do all of their new products like the Pro-10).
Hensel is a well respected and long-time name in the lighting game, among other top-notch European brands like Elinchrom, Profoto and Broncolor. We fully expect these units to be of top quality and performance. Check out some photos below.