Microwave has good information - things change!

We were scheduled on 737s Monday, SFO - LAX:

AA 1923 Lv 1220 - cancelled (no obvious reason, but cancelled nonetheless)

EXP protected us on AA 2246 (which had at least five delays recorded against it - largely SFO weather, I suspect, but we'd have missed our connection)

We were able to arrive early and boarded AA1920, which was ultimately cancelled for mechanical problems (deployed and unretractable trim tab on aileron) (had it gone it would have been with a subbed aircraft)

Off topic: Ultimately, we were Rule 80'd to a UA flight (which apparently screwd up our tickets sufficiently to cause my wife to be denied boarding at LAX on IB 6170 to LAX we had to hassle AA and IB for two hours to get her BPs).

As well, luggage (yeah, we checked this once!) did not get transferred properly, so to date, no luggage and no updates on location of luggage for our pending cruise. (This is the abridged version; it was much more complex and frustrating than it sounds.)