Well, I think that obsessions with scary things tend to come and go in trends, and this one was on everyone's mind back when -- OH MY GOD! I'M BURNING! SOMEONE HELP ME! AAAARGGHH!ASLJDFJJFDSLJGVCJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ

Okay, that was my smart-ass answer, but here's my real one: Like I said, obsessions with various "paranormal" phenomena tend to come and go in trends. People lose interest because conclusive evidence in favor of the strange thing never surfaces. And although most people don't hear them since they don't make for interesting stories on talk shows and quasi-news magazine shows, more mundane explanations usually come to light. Here's a good rundown on spontaneous human combustion from my absolute favorite source of knowledge, The Straight Dope:

http://www.straightdope.com/classics/a1_205b.html

For recent SHC stories check out Fortean Times. They're chock full of other weird stuff as well.

http://www.forteantimes.com