Is there any chance that the Mach4 Galil plugin will work with MachPro?

Doesn't look like it at this time. Paul Stephens works for MachPro, I'd assume he'd know.

The Mach4 Galil plugin will not work for MachPro.

Modules,  Wizards, and PMC's can move over - assuming the dependencies are there and available for the object to move over. 

Any plugins will need to be compiled for 64bit applications in order to function.