With an official (not just voluntary) recall looming, with the media being all over them and airlines banning the Note 7, it's pretty clear that Samsung has massive problems. But consider this: what will happen if another Note7 goes up in flames once the devices have been exchanged? And the likelihood of that happening is somewhere near 100%. The Note7 uses USB-C - a standard that has been under scrutiny because of fires started by 3rd party cables and chargers (even expensive ones). Plus any phone can go up in flames, as faulty or damaged lithium ion batteries are relatively frequent - just google "iPhone burns".
So what happens when another Note7 burns or blows up? I'm guess there'll be drastic, worldwide media backlash, no matter why exactly the device ended up going up in smoke.
And what if it turns out that other Samsung devices also went up in flames (which is, again, very likely, for the reasons mentioned already)? Samsung devices are already developing a reputation of being dangerous - one of my students last week jokingly said to another sitting next to him that he should turn of his S7 EDGE as he's afraid it might blow up. Just a harmless joke for him, but the reality is this: "Samsung = dangerous" is likely going to influence people's buying decision over quite some time.
In any case, I seriously doubt that the Note7 will make a massive return - enthusiasts (myself included, although I also pre-ordered an iPhone 7 Plus) will buy it again, but the general population might not. I find this somewhat heartbreaking - Samsung has finally emerged from its shell this year, producing fantastic devices again. The Note7 is easily the nicest mobile phone, both from a hardware point of view and from the software experience, I've ever owned. I find it heartbreaking, that an extremely minor issue, probably affecting only a handful of devices, could potentially ruin the company.