I've never heard of it outside of ENWorld. Remember that who posts here isn't exactly a represenative sample of D&D players, the people who post and read here are the subset that are online, interested enough in D&D to read message boards about it, read more than just the WotC boards, and probably care about 3rd party products. While we are a fairly dedicated, and decent sized group, we aren't even close to being all of D&D players.
Any fad or trend here isn't inherently indicative of the larger gaming world. It just shows what one particularly dedicated but small subset is going with.
From purely anecdotal evidence in my life, C&C is another highly niche product that the vast majority of gamers will never see or probably even hear of. It's not in stock at my FLGS (which is still the main way I know people to get gaming books). Nobody else in my own gaming group of 7 players had ever heard of it (I brought it up in conversation out of curiosity), and in the two dozen or so of my university gaming group, only the 2 others who read ENWorld and keep up with 3rd party releases had ever heard of it. The vast majority of D&D gamers I know aren't interested in "rules light", they devour the new base classes in the Complete books and still love to come up with powerful character builds, or they just play the game and don't think too much about whether the system is too complicated or simple.
Most D&D gamers I know still think that 3.5 is a lot simpler than 1st or 2nd Edition (including 2 veteran 1st edition players playing in their first 3.x game under me), and while you can come up with fine rules points to complicate things, it's still a helluva lot simpler than what came before, and a whole lot simpler to teach to newbies than 1st Edition.
Now, that's strictly anecdotal, but it's how things look from this person's perspective.