Obviously from this discussion not everyone would buy it, but I
certainly would as long as it wan't cost prohibitive. A year and a half
ago I cut the tip of a finger off on my PM66. I really wish I had been
working on a sawstop equipped saw. Sawstop isn't a hard sell to me at
all. $100/cartridge + a new blade? So what? Want to know how much
cutting my fingertip off cost? About $6000. Mosly covered by insurance,
but cost to me was still more than the $200 it would have cost to get
back on track after a sawstop trigger. In other words I would be _very_
happy to shell out $200 every time I would have cut my fingers off but
didn't because the brake triggered. Clearly the general strategy would
be to never get into a situation in which you triggered the thing at
all, but as I have learned sometimes accidents happen.

I think the reason saw manufacturers don't want to use it is probably
one of two things:

1) the manufacturers are really lazy
2) the terms being offered to them to license the technology are too
expensive

Lazy?
My theory is that the manufacurers are loathe to redesign their
products and retool their production facilities, because that is way
more trouble than just continuing to pump out what they already make.
The reason the PM 66 is called the 66 is because it hasn't been
substantially changed in design for the last 38 freaking years.
Comparing my '72 PM66 and my friend's new one, the few minor changes I
noticed were obviously to slightly cut production cost, not to improve
the design. It would be pretty straightforward to redesign the arbor
casting and cradle to accomodate at the least a riving knife. But they
haven't even bothered to do that, much less the more serious
modifications that would be required to design in sawstop.

Terms too steep?
Some saws/brands have higher margins than others, but generally I bet
the manufacturers are not making a huge profit on such a commodity
product. Adding cost to the production would mean either cutting their
margins or charging way more by the time distribution and retail
markups are included.

I think of this technology exactly like airbags in cars. It adds some
cost. Some people don't think the cost is worth it. You can certainly
buy cars without airbags. But I am willing to pay a little extra for
that additional protection. Hopefully you never even have the
opportunity to get your money's worth out of the system, but it is
there in case you need it. (I actually don't have a car though, so
we'll see in the future I guess).

The other comment I had the number of table saw injuries. Most
table saw injuries are related to kickback, which sawstop woudn't help
with in most cases. However, the second place injury is lacerations,
which along with kickback related incidents where the kickback drags
people's hands into the blade would be helped by sawstop.

-Holly