I did end up getting an upgrade at the gate, and, as it turned out, the flight BWI-SLC was great--our ship, N3746H, had AVOD, breakfast was decent, the FAs provided constant service all the way to Utah, and the seat cushion was comfortable.

The flight ended up 100% full in both cabins. The last upgrade was given to a lady with no SkyMiles status, who seemed stunned to be in F.

This begs a question--if rows 11 and 12 were supposed to be for elites only prior to the day of departure (and only 11E was not spoken for), and 10 out of 12 seats in the exit rows were spoken for as well, this would mean that there were 21 pax qualified for an upgrade (there were 10 seats in F open an hour before flight time). That was clearly not the case yesterday. Why is DL giving out seats in these rows to non-elites?