I guess I am not sure that it is necessary. If you have DVD, it's just so easy to go in and choose the core only premixes, so I can't think what the point in a separate ab/core DVD for DVDers would be. However, if you haven't made the switch to DVD yet, I can see why you might want an Ab Hits 2 (get rid of all that rewinding and fast forwarding).
Maybe post this on Cathe's "Ask Cathe" forum or on her "Future Workout suggestions" forum, where she will see it more readily?