I'd be a hypocrite if I said he was my favourite bassist or singer, but of course I knew about him, I heard his (and O-'s music) and I feel his sudden demise was highly unexpected and tragic.
Was never a fan of their sappy Gothic/Doom Metal. But Peter Steele had a nice, deep voice. I also liked their song "Love You to Death". I've heard this news already on a few other metal forums. RIP.