I hate to even think of what would happen. I'm a single parent to an only child and I take care of my parents because my brothers aren't interested and don't live close to them. Since I got divorced, I've had to make more of a plan about what will happen in the event of my death, but it's nearly impossible to talk to any of my family about it because they think I'm being morbid (an odd thing, but ever since I was very young, I had a feeling that I was going to die relatively young, or at least have an unnatural death before I was 50).
Anyway, I imagine my family would be shocked and devastated, my co-workers would probably be sad for a while and my friends would probably be shocked and sad too. At least I hope my death would be sad for someone.