See, at the point where people aren't eating cheese or eggs, I'd call them vegan, as opposed to vegetarian. That's how I've always understood the distinction.
I suppose that much of it comes down to your reasons behind vegetarian/veganism. Someone who feels very strongly about the ethics of livestock production would probably be more inclined to avoid marginal items like gelatin than someone who's simply in it for health reasons. All the vegetarians I know fall into the latter category. The couple of vegans I know fall into the former.
Personally, I was put off Jello for years because, when I was 8, my older cousin told me it was made from feet. When I got older and understood how many levels of processing there are between the actual animal by-products and, for example, my rice krispies treat, I wasn't bothered anymore.
