Looks like quite a deal, especially to places like MSP (matched by NW) and DFW (matched by AA). Other places also might draw matches. Book through 1/18 only, and lots of day/time restrictions (before 9 a.m. only, no Fri & Sun + some blackout dates). But: can use for one-way, at least on FL.
They managed to fit their sale period entirely into a slot where I can't use this one...aargh.
Hope it's useful to someone else.