No, the title of this thread is not what you think it is. It's NOT about someone dying at the con, but someone famous that we may know, in some way.
I don't know whether it's a curse, but in the five years I have been to anime cons, someone famous dies before I attend it for the first time! (Or more rarely, during it.)
Some examples:
SakuraCon 2006 (my first con EVER): Peter Tomarken, host of Press Your Luck dies in a plane crash less than two weeks before it begins.
KumoriCon 2008: A double whammy, but the first death is Trailblazers star Kevin Duckworth, who dies of a heart attack, and during day 2, Don LaFontaine, best known for being the voice of many commercials, movie trailers, the like, dies of a collapsed lung.
Anime Expo 2009: Hoo-boy. This was a real doozie. We lost Farrah Fawcett, Billy Mays and Michael Jackson. Wow. AX09 became like MJX during the whole time, looking back.
FanimeCon 2010: Two deaths: First of troubled ex-child star Gary Coleman, and veteran actor Dennis Hopper (some of you recognize him from as King Koopa from the Super Mario Bros. live action film).
AkiCon 2010: The famed Wheel of Fortune announcer, Charlie O'Donnell, passes away from heart failure.
What do you think? Am I cursed, or is this all badly timed? You decide.
(But, as a sidenote, I do try to pay tribute to the deceased in my own special way.)