I'm sure that MTH will keep the design that SHS had and have everything designed so that converting to Kadees or SHS's "Kadee Clones" will be easy. BTW: Kadee couplers for S scale are the #802 (black) and #808 (brown). Same design, but different colored plastic. The SHS "Kadee Clone", IIRC, were a design used for close coupling on their F-units.
I know it wasn't mentioned, but on the wheelset front, MTH will still sell scale wheels (which is good news for the scale folks). However, from my understanding, they will be available as a separate item only, rather than included with their products like what SHS was doing and including them with their locomotives (with the exception of the 2-8-0) and rolling stock.
Robyn (CarolinaRail)