Toyota has been phasing black boxes into its cars since 2001, but stresses that the data collected is for "general safety research, not accident reconstruction." The data collected comes from several collection points like the acceleration and airbag modules. While it can help solve a case like the one of the zooming Prius in New York, where the woman was actually pressing the accelerator and not the brake, in other cases it won't prove effective, such as when the data being gathered is from the same corrupt source that's part of the problem.
The National Highway Traffic Safety Administration has laid out some uniform regulations to cover black boxes from 2012. Just about every automaker selling cars here uses them, but they collect different data and an owner's access to that data differs across the country. Carmakers are generally in agreement with the new regs, but want to push the date back a year to fall in line with vehicle development timelines. The bigger issue, though, isn't what a black box is going to record, but what it will do with those recordings, who can get to them, and how easily.
[Source: USA Today]