There are plenty of knives out there with a glass breaker on the end.
My personal (uneducated) opinion on knives designed with the pommel strike in mind:
There may be some knives that advertise this feature, there are some where it is obvious (Spyderco Yojimbo), and there are some where it is just built into the knife as a natural result of the design process (Emerson Commander). Most of these have in common a part of the end where the handle forms a small cross section. The small cross section in theory (and practice if you believe James Keating) facilitates the user to concentrate a large amount of force onto a small area, acting as a “force multiplier”. While it’s not so much “mall ninja” as it probably is “having the best to defend you”, the purpose driven strike pommels (made up term) probably do make a difference. Thing is, how much of a difference do they make? Take a Spyderco Yojimbo, and a Buck 110 and use both to beat on a 2x4, and see how more effective one will be over the other. Guaranteed that if you thump someone with a 110, they are most certainly going to feel it! Datu Kelly Worden actually designed his Worden Tactical to be used as a sap, and the end is quite rounded. Fact is, most folding pocketknives have handles that are so small that they will act as a force multiplier, without the additional decrease in cross section.
The principal is the same with crenulated bezels on flashlights. The “strike bezel” may (or may not) have the ability to create more cuts, thereby drawing more blood when used as an impact weapon, but a regular bezel of an aluminum flashlight is a devastating weapon in it’s own right.
I once had an online conversation with Chad Los Banos in which he told me of how he tested an Endura (now Endura 3) on a sheet of plywood, and put some serious dents in the wood. This is a squared, FRN handle with no steel in it whatsoever. If you get hit with it, there probably won’t be much difference than if you got hit with a Yojimbo. They are both going to do some serious damage. I think this is one of those areas where, it’s not the size or caliber, but shot placement that is more important.
Just my $.02.