I was just chatting with Sven now, he speculated that he might have died a while ago, but kept everything secret for the iPhone 4S launch. I noticed that nowhere does it have his actual date of death, all the articles just say he "died".

I did notice a slight apprehension in those on-stage when watching the iPhone 4S event video, but that might not necessarily be attributable to Steve dying on Monday or Tuesday.

EDIT: Ah, it seems a statement from his family said "today", meaning today.