I'm not in favor of yet another federal law regulating products we use and should be responsible for ourselves. Besides, such federal laws (and I'm talking about the US federal government here, not state and local gov'ts) are unconstitutional because the US Constitution only grants those powers that are specifically stated in it. Anything not specifically stated in the US Constitution is reserved to the states and the people (see the 10th Amendment). Yes, I know that our fedgov routinely tramples and violates the Constitution, but that's another topic!
Back to brake rotors: most of these cheap aftermarket brake rotors are aimed at people who install them themselves (i.e., do-it-yourselfers). Most auto repair shops, well, the reputable ones at least, will either refuse to install these cheap rotors outright or will make you sign a waiver denying warranty coverage after installation. They don't want people coming back to get a defective or inferior quality rotor replaced; they lose money that way!
As DIY'ers (which a lot of us on a site like BITOG are), we have already decided to take responsibility for care of our own vehicles. We need to extend that responsibility and care to the parts we choose for our DIY jobs, especially a critical component system such as brakes. Yes, good brake parts (such as Wagner) probably cost twice as much, or more, than the cheap Chinese knockoffs that are flooding our market, but they last a lot longer and meet or exceed OEM specs as well as perform better.
Those companies that falsely advertise their products as meeting or exceeding OEM specs should be reported to and prosecuted by state attorney generals and local officials; there already are laws against fraud! Let's vote with our purchasing power and force the chintzy Chinese [censored] off our market by choosing good quality brake products! It will be safer and more economical (better value for the money) anyway.
Popular Mechanics magazine did a report on cheap brake rotors in the Dec. 2009 issue:
http://www.popularmechanics.com/automotive/how_to/4338268.html