Today's flight #327 LGA-MKE: Successful upgrade!

I also just discovered an interesting quirk of the FL website. If you look at your booked flight more than one hour before the flight, you can access the seat map for your flight. As long as you don't close that window, you can refresh the seat map even after the flight has begun (via gogo).

For today's flight, at T - 1:05 the map showed 4 available biz class seats. At T - 0:40 I got my upgrade; a few minutes later I refreshed the seat map and it showed my seat as now occupied. Just prior to boarding, the seat map showed only two empty seats in biz class. On board, I noticed that only one biz class seat was empty; refreshing the seat map showed the same.