Btw, the bubble thing posted previously, looks very nice, but is out of WP world.... doesn't fit at all. imo
How would cortana know you are about to utter a command?
What do you mean? It could be like that - if there's a reminder for a meeting, she can read that out loud and then ask if you are attending or running late, etc.
If the phone hasn't been moved for an hour, this could mean that you are not nearby then she won't expect you to reply (and won't read out loud the reminder).
I know there are exceptions, that's just a thought.
The best part of that entire video is when it showed that quiet hours will automatically turn on when I'm "busy" in meetings....can't wait for 8.1!!