Evidently, Woz's speech is the opening keynote, which is typically the biggest and most prestigious one (ASIS lists it for Wednesday morning - first exhibit day). This, in particular, suprises me. I thought the non security, light keynote is typically on the last day (Neil deGrasse Tyson, Dave Barry, etc.).
I read about Woz from Steve's Biography and found to be immensely talented person and a thought leader. His speech will defintely bring value, but as far as Security Industry goes this is intriguing if he has something very very specific to offer.
I voted as "Good Idea", because overall for ASIS I think Woz will offer some cache and draw people to the ASIS event in general and the keynote session.
Personally I think it's more "bad idea", I'm not sure what relevance Woz really has to anything. Not trying to bash him, he is just sort of the Paris Hilton of the geek crowd, nobody is exactly sure how or why he stays relevant, yet he does.
ElBaradei is pretty well known worldwide for his work with the IAEA. His work as director of the IAEA was focused on making it harder for countries to develop nuclear weapons. Both his talk and Gates' were extremely timely as they focused on securing nuclear weapons and peaceful proliferation. In the weeks leading up to ASIS there was talk in the news of the U.S. and Israel exploring what military actions were available to deter Iran from making a weapon.
As for Woz, maybe he can talk about the recent Apple hack?
My first was Pervez Musharraf, and he was extremely interesting. Like John said re: others up there, not purely security related, but related to the state of the world, terrorism, national defense, etc., which is of great interest to CSOs out there.
There are definitely worse choices than Woz, but I doubt it'll be all that pertinent. He seems more like the type they'd use as the closing day luncheon speaker.
Take your example. You had the head of Homeland Security and a former Defense Secretary who are clearly valuable to that audience. The International Atomic Energy Agency guy may not be as big a name as the others but he too was relevant to security (nuclear security/threats). It's not as useful to manufacturers or integrator but for security managers/execs, it's germane.
I get Woz is more of a personality but is that enough? Why not David Hasselhoff then? Or have Jeff Ross speed roast CPPs?
I know ASIS sometimes gets people only tangentially related to security but this seems really weird and extreme even by their standards. Woz is a nice guy and entertaining but how is this related in any way to security?