This is probably the best solution to this problem that I have seen. I've seen other technologies that will automatically stop the blade, but they all involve some sort of sensor that is installed in the guard or the fence. The problem being is that most general contractors remove the guards right from the get go.
Moving on to Gub'ment regulations... you don't even have to worry about it, some sort of safety interlock feature like this will eventually become the law of the land. Either the government, insurance companies, or saw makers themselves will make this mandatory. You can rest assured that once all of the major competitors have similar working designs, they will bribe congress... er I mean lobby congress to put this into effect. That's because they get an extra boost in sales when millions of companies are forced to buy new saws to keep up with the regulation.
On a side note, I have found that corporations and bureaucracies can produce some truly strange outcomes. Here's an example... during the salad days of the Space Race, my company used to maintain and operate their own private fire department. Some time during the 80's a bean counter decided that it was a waste of money, and now the company contracts out with the city for fire fighting services. OK, since I work in a building that contains flammable materials, OSHA stipulates that fire extinguishers must be placed liberally throughout the building. Great. And since I work near fire extinguishers and with flammable materials, Cal-OSHA requires that I must be trained on how to properly operate one. So the company spends money training me on how to distinguish the different types of fires, and which type of extinguisher to use... on and on. Not just once mind you, I have to re-certify and go through this training on an annual basis.
Now here's where it gets stupid. The company's insurance underwriters don't want employees fighting fires. Period. Which means, despite the aforementioned training, we are instructed that if we see a fire, we are to leave the area and call 911. And as mentioned, the local city fire department will arrive to fight the raging blaze. So now we're going to enter the Twilight Zone. Due the secure nature of the building, and the fact it contains chemicals that water can NOT be used to extinguish, the building is on the city's "let burn" list. Meaning the fire dept. will simply watch it burn. Their sole purpose would be to prevent nearby building from burning down.
So thanks to a combination of overlapping and contradictory government and market based regulations (mixed in with a dose of good old fashioned penny pinching), an able bodied and trained person (me) is supposed to walk away from a fire and stand outside with the firemen to watch it burn.