I flew JFK-MEX Friday and its still a mess - fortunately I was upgraded on-board. At check-in for JFK-MEX, I asked the DL checkin agent about my upgrade and she said called the gate to see if she could clear me. The gate agent said on the phone to the checkin agent that I could get upgrade for $250 immediately or see if space is available at the gate before boarding (I declined). At the gate, they called a bunch of names to the counter and new tickets were reissued (mine wasn't). I boarded early and sat in my seat while the plane filled up. Right before boarding finishes, the gate agent comes on the planes PA calling my name. When I identify myself, they moved me up to 1A (the 787 went out with 3 seats open in F).