ZigBee and Zigbee Pro interoperability
The simple answer is yes, as long as they use the same frequency range and bitrate, as there are multiple options for these in the standard.  This means physical layer interoperability (i.e. if you wrote the code for one or both, the modules should be able to talk to each other), not application-layer interoperability (i.e. any two random devices with a Zigbee logo on the box will not necessarily have anything meaningful to say to each other :)