You're kidding me - 68? I dunno why but I thought he'd be much younger than that. They'll absolutely never replace that voice, no way. It'll be sorely missed. It's a Hollywood-defining voice over. Nothing says movies more than that deep bass rumble.
Film and tv show trailers will never be quite the same. This guy is probably the biggest, yet least known, legend in popular media. He shall most definitely be missed.