My condolences for your loss. There was just a thread a week or two ago about someone who had stopped posting some time back who had turned out to have passed away.

I can't really think of any good way for the board to know if someone has passed, though. I mean, I registered for my FT account with an email address that I don't use for anything else (i.e., none of my friends know it). I have a few friends on FT who know my real name, but these are mostly internet friends... they probably wouldn't know if I had passed away in the night (wow, that sounds sad).