Those old systems are difficult target for both companies (Hyperion has announced support for BPPC and CSPPC based system, although their releases are quite imaginary at this point), so we'll apparently must wait and see what will happen.
Some people are going to have to choose depending on what hardware they have..
MorphOS: Doesn't support Mediator, supports Grex
AOS4: Supports Mediator, doesn't support Grex
At least, this is how it stands AFAIK.
