My crystal ball says if AA cannot get more A319s, they may be forced to look at CS100s. (Delta has an order in and the 2 European carriers flying them give them rave reviews.)
After all the MD80s go away (and the E190s), there is a need for a plane somewhere between the 737 and the regional 76 seaters.
May not be first choice for type consolidation, but the hand may be forced. I have no vested interest but the videos of the cockpit sure look sweet, and it has the look and feel of a mainline for the PAX. (Kind of reminds me of the old DC-9s in size, but completely clean slate and modern.)
Again, just my opinion, for what it is worth.