I doubt it had anything to do with a keynote speaker. This was simply a vacation for Brad and Ray, and now that Ray is sick it would be too boring for Brad to go along so they simply postponed it...
Kind of reminds me of when they delayed Lucent verification of co@ocx because of "enhancements".
I sat a few feet away from John Howell in Oregon years ago when he said flat out that PR was a lie that they were covering for one of the engineers they couldn't find at the time. He freaked out as he couldn't get the concept to work for lucent test and left.