I'm not pleased with this change at all. Those of you suggesting it's not that big a deal probably haven't tried a pure Backlash build:
The entire point is to use Cyclone Strike to bring EVERYONE to you so that they can swing at you. You trigger AoE explosions that are at their strongest when you're completely surrounded. Only being able to pull 8 monsters defeats the purpose of this rune and the damage does nothing to change this. Damage doesn't matter because other abilities far outweigh the damage it could ever do.
A single use of Wave of Light with Explosive Light is superior to Cyclone Strike both before and after the damage change.
100% (or 313%)
vs 430% (with a MASSIVE range)
Then you have SSS, LTK, SW and a slew of other abilities that are all better than Cyclone Strike at dealing damage.
This is a nerf, plain and simple.
If you want to argue that the nerf was needed because of CM abuse I call shenanigans. Changing everything BUT CM to address CM's problems is not how this game should be handled. I hope Blizzard didn't make this change because of CM because I'm getting awfully tired of bandaids that are wrecking build diversity.