I think that it's mostly the latter, due to Katrina/Rita and TV shows such as Man vs. Wild, Survivorman, It Could Happen Tomorrow, MegaDisasters, et al.

I started to get interested in in survival when I was in the Boy Scouts, and from a little board game called "Wilderness Survival by Avalon Hill. I'm not afraid to admit that Katrina/Rita woke me up and refocused my attention on survival requirements. I find that being survival oriented helped my self-confidence and interest in self-sufficiency. Plus, discovering this website was a godsend because of the information, great people and fascinating topics on the boards.

Perhaps it's also important to consider not just who is interested in survival prep, but rather who is planning to stick with it.