By now, everyone is aware of the SawStop technology and it is pretty well understood that it represents a huge advance in table saw safety. And now that riving knives are required on all new table saws sold in this country, it would seem that safety is being taken more seriously in general. But it does not end there. New ideas are appearing now and some of them are looking very promising.
For example, take a look at the Whirlwind (www.whirlwindtool.com). This is a blade guard that is designed to maximize dust collection but which also incorporates a saw brake that is triggered by dangerously close proximity to the blade. This is different from the SawStop in that it does not require contact to trigger and does not necessitate brake replacement to restart. It simply shuts down the motor. It has a one second shut down time whereas the SawStop activates in micro seconds. But since the activation does not require actual contact with the blade, a one second stop time would be sufficient to prevent most injuries.
Of course, if you are in a situation in which the blade guard must be removed for a particular operation, the Whirlwind would be defeated whereas the SawStop brake would still be effective.
There is probably never going to be an "ideal" safety technology that will cover every possible scenario. And these devices are not yet available for other machines like the band saw or radial arm saw. But the trend seems to be moving in the direction of devices that actually increase safety rather than simply comply with some obscure regulations. It will be interesting to see how this develops over the next couple of years.