It's already been nerfed. The proc rate was decreased in 1.0.5 I believe.
There is nothing wrong with most builds using it.. it's not broken, it's just better than most anything. Every Monk uses One with Everything and I would bet that 95% of Barbs use Weapons Master... doesn't mean they are broken
I choosed Top 500 by Heroscore but for Top 500 by DPS is almost the same thing. The stats may not be representative but I never thought kitting builds are so unpopular. At least in softcore, because in hardcore Hydra has above 40%.
So all in all the 1.05 didn't diversify builds that much. At least for wizzard I see that wirlwind/HOTA ratios are around 50/50.
So CM nerf incoming?
Kiting is a build most suitable for lower geared characters. You can't get this data. Also, there is not "one single kiting build", in contrast to Archon or CMWW builds which are pretty much straightforward and all the same.
Regarding CM, maybe, yeah. If a skill is used by 99% of the population, Blizzard tends to nerf it, this is something that happened very often in the past. Wouldn't be surprised if they changed something. What I personally would like to see is a critical hit chance cap, however, that would still leave CM fairly powerful, but maybe scare some away. On the other hand, the majority of wizard passives is completely useless.
The lack of build diversity is mainly evident at high gear levels because Archon and CMWW are simply two of the most efficient builds out there. Other builds can compete at various MP levels but often are slower for farming low MP or hard to survive with at high MP. Still, they exist and lots of people use builds besides the traditional Archon or CMWW.
Also, CMWW has several variations, including using different Armor spells, a few different passive choices, different runes for pretty much every skill except WW, and even the choice of your 6th skill slot. I imagine that's not the same build diversity Blizz was thinking about when 1.05 launched, but with that much versitility combined with the high efficiency of the build at high gear levels, it's hard to find another build to match.
Another reason kiting builds are going extinct is because gear is getting cheaper so it's much easier to gear above the content and faceroll with Archon, plus Kiting builds are horribly inefficient compared to the other staple builds. There's guides showing you how to get 100k+ dps for 1mil gold or less, so just about any fresh 60 can faceroll through MP0 with Archon, so there's no need for a kiting spec.