>"Don't see much of those Gaz cartridges around much anymore."
I can buy fuel a fair bit cheaper in Gaz canisters locally than in MSR canisters, mostly because Gaz is stocked in 230 and 450 grams while MSR is stocked in 113 and 227 grams.
>"I suspect they will fall to the roadside too."
I'm by the roadside, but just barely - I'm at the western extreme of the North American road system. 5,000 people in town, but a lot of people come from all over the world to play with their food (hunting and fishing).
With how strong Gaz is in France and how the French patronize anything French, I suspect it will remain dominant in France, moderate in Europe, and a minor player in North America. Anyone know if that propagates out into Francophone areas around the world? Quebec, former African colonies, etc? British East African countries still are tied to British de-facto standards even while being upset at their former rulers.