Interesting stuff Matt!
But as I read your detecting pedestrian traffic... the negative part of my brain immediately started firing all kinds of conditions that would provide unwanted results.
1 - Wife sick in bed (went to bed early) while I stayed up to watch some space show on the Science Channel. I go up to bed usual time and bang the wife gets hit with lights when I wouldn't want to disturb her.
2 - Wife going one way down the hall while I travel the opposite...
It's always the gosh-dern people that get in the way of a really good HA solution isn't it?!?!
What I'd really love to see is a truly good 'person tracking mechanism' (asking for the world) thats affordable and reliable. In many cases motion sensors just don't cut it... either the person stopped moving enough to trip it or whatever... A nice body heat sensor mechanism and if it had some way to detect multiple body heat signatures and report a occupancy count that would really be nice.
Oh well... back to watching my dvd reruns of star-trek...