They have been around for a while:
"O.Symetric Harmonic rings were tested independently in 1993, a 16km road test suggested they increased power by 33 watts and 1.5kph; a saving of 45 seconds in total.
Rotor Q-Rings, a newer product, were tested more recently by Spain’s Universidad de Valladolid. Their study from 2006, conducted on elite U23 cyclists, compared sprint power, sustained power output and subsequent blood lactate response versus standard chainrings. The Q-Rings proved superior in every test, delivering a 12 watt gain in sustained power, 30 watts in sprint power and a nine percent reduction in blood lactate concentration."
I just got myself some of these and will post my findings on my blog. Hoping for some added speed.
Although its really difficult to quantify their power effect in numbers,the one review that sold me on them was this:
Think of pedalling at a given high wattage on a flat road. It's difficult to hold, then incline the road 2% and hold the same wattage - it's much easier to hold a higher wattage on a hill than a flat, that's what these rings give you.